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Objective: Polyphenols extracted by table grape have been demonstrated to decrease cell proliferation in vitro and to exert anti-atherosclerotic and antithrombotic activities, regulating cell functions. A grape polyphenolic profile is affected by climate as well as a grape cultivar. This study was aimed to characterize the berry skin polyphenolic composition, antioxidant activity and antiproliferative properties of two black grape cultivars, Autumn Royal and Egnatia., Methods: The phenolic composition of Grape Skin Extracts (GSEs) was determined by HPLC analyses. The antioxidant activity was determined using DPPH, ABTS and ORAC tests. Caco2, HT29 and SW480 human colon cancer cell lines were used to test the effects of GSEs in vitro. Cell proliferation and cell cycle were assessed with the MTT method and a Muse cell analyzer, respectively. qPCR and Western Blotting analysis were used to evaluate gene and protein expression, respectively., Results: The total polyphenolic content and the total antioxidant capacity were significantly higher in Autumn Royal than in Egnatia. However, table grape Egnatia showed greater ability to affect cell proliferation and apoptosis, as well as to exert a growth arrest in the S phase of the cell cycle, particularly in the Caco2 cell line., Conclusion: These data suggest that the new grape variety Egnatia is an interesting source of phenolic compounds that could be of interest in the food and pharmaceutical industries., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Chronic inflammation increases the risk of developing certain types of cancer, such as colorectal cancer (CRC). The oxidative metabolism of polyunsaturated fatty acids (PUFAs) has a strong effect on colonic tumorigenesis and the levels of arachidonic acid (AA) and eicosapentaenoic acid (EPA) can contribute to the development of an inflammatory microenvironment. Aim of this study was to evaluate the possible differences in the AA/EPA ratio tissue levels between CRC patients with and without synchronous metastases. Moreover, the expression of the most important inflammatory enzymes and mediators, linked with the AA/EPA ratio, have been also assessed. Sixty-eight patients with CRC were enrolled in the study, of which 33 patients with synchronous metastasis. Fatty acid profile analysis in tissue samples was done to examine the levels of AA and EPA. High levels of the AA/EPA ratio were detected in tumor tissue of patients with metastatic CRC. Moreover, an increase of expression of the main enzymes and mediators involved in inflammation was also detected in the same samples. The lipidomic approach of inflammation allows to evaluate lipid homeostasis changes that occur in cancer and in its metastatic process, in order to identify new biomarkers to be introduced into clinical practice.

Background: Adherence to a healthy diet has been reported to be essential for the primary prevention of colorectal cancer, through a reduction of tissue inflammation, a low concentration of circulating lipoproteins and lower levels of serum cholesterol. Since an altered expression of the fatty acids pattern has been demonstrated to be a crucial event in colorectal carcinogenesis, lipidomic analysis is considered able to identify early diagnostic and prognostic biomarkers of complex diseases such as colorectal cancer., Methods: cell membrane fatty acid profile and serum lipoproteins pattern were evaluated by gas chromatography and electrophoresis method respectively., Results: There is a close association between diet and lipidomic profile in colorectal cancer, both in pre-clinical and clinical studies. A modified serum lipoproteins pattern has been demonstrated to be predominant in intestinal tumors., Conclusions: The study of fatty acids profile in cell membrane and the evaluation of serum lipoproteins subfractions could be useful to have an integrate vision on the interactions between lipids and the pathogenesis of colorectal cancer and to understand the mechanisms of action and the consequences of these interactions on human health status.

Background/aim: Riboflavin transport in enterocytes is mediated by three translocators: RFVT3 located on the apical membrane, and RFVT1 and RFVT2 on the basolateral membrane. The aim of this study was to investigate whether the expression levels of RFVTs are altered in human colorectal cancer (CRC)., Materials and Methods: In human colon adenocarcinoma cell lines (CaCo2, DLD-1, HT-29) and in tissues of patients with CRC, gene and protein expression levels were evaluated by real time-polymerase chain reaction and western blotting. Intracellular flavin content was determined by high-performance liquid chromatography., Results: RFVT3 and RFVT2 gene and protein expression levels were higher in DLD-1 and HT-29 compared to Caco2 cells. In HT-29 cells, the RFVT1 protein level was drastically lower. These differences are presumably responsible for the higher total flavin content in DLD-1 and HT-29 cells. In tumor tissues of patients with CRC, RFVT1 content was reduced at both protein and mRNA levels compared to normal mucosa. RFVT3 and RFVT2 gene expression levels were increased, while protein expression was reduced, with a small reduction in riboflavin amount., Conclusion: This study provides first evidence that transcription/translation of RFVTs are profoundly altered in CRC., (Copyright© 2018, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

The early detection of colorectal cancer and determination of its metastatic potential are important factors to set up more efficacious therapeutic strategies. In the present study, we hypothesize that fatty acids analysis in colorectal cancer patients can discriminate between metastatic and non-metastatic patients. Fifty-one consecutive patients with histologically proven colorectal cancer were enrolled in the study and the presence of synchronous metastasis was detected in 25 of these 51 patients. Fatty acid profile analysis in red blood cell membranes was not able to discriminate the metastatic colorectal cancer patients from those without metastasis. However, significant differences in the tumor tissue fatty acid profile were found in metastatic cancer patients when compared to patients without metastasis. Metastatic patients showed significantly lower percentages of Eicosapentaenoic acid (EPA) and higher levels of γ-linolenic acid (GLA), a n -3- and n -6-Polyunsaturated fatty acid (PUFA), respectively. Our findings, suggesting that membrane lipid rearrangement could influence the cellular function and make the cell more prone to metastasis, offer the opportunity to develop nutritional strategies that may be helpful in the prevention and treatment of colorectal cancer., Competing Interests: The authors declare no conflict of interest.

Background/aim: The study of fatty acid composition of the erythrocytes' membrane can be considered an appropriate biomarker for investigating the relations of the pattern of fatty acids metabolism to a specific disease. The aim of the present study was to analyze the fatty acid profile in red blood cell membranes of patients with colorectal cancer (CRC)., Materials and Methods: Thirteen patients with CRC and 13 patients with no malignant disease were enrolled in the study. Fatty acids were extracted from erythrocytes' membranes and quantified by gas chromatography. The data were analyzed using the Mann-Whitney test., Results: Patients with CRC showed significantly lower mean percentage of n-3 polynunsatured fatty acids (n-3 PUFAs) than controls (5.1% vs. 8.0%, respectively). This finding was reflected in the higher ratio n-6-PUFA/n-3-PUFA observed in cancer patients., Conclusion: Lipidomic analysis of erythrocyte membranes confirmed the presence of an altered fatty acid profile in patients with CRC., (Copyright© 2014 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.)

Purpose: Fatty acid synthase is a common phenotype to various human cancers including those of prostate, colon, lung, endometrium, and stomach. Increased fatty acid synthase levels have been detected in serum from patients with breast and pancreatic cancer. In this study, serum levels of fatty acid synthase were measured in colorectal cancer patients at different stages of disease., Methods: Consecutive 67 patients with colorectal cancer were enrolled in the study. Serum levels of fatty acid synthase were examined by ELISA test. The Kruskal-Wallis test and the χ (2) method for trend have been used to analyze data., Results: Serum fatty acid synthase levels of patients belonging to three groups of stage disease are statistically different. The patients with stage III and IV have significantly higher serum levels of fatty acid synthase than patients with stage I-II. There is a positive trend in serum fatty acid synthase levels from stage I-II to stage III and IV of disease., Conclusions: Fatty acid synthase levels are associated with the stage of disease in patients with colorectal cancer.

In this review, we summarize recent progress regarding the study of the main enzymes of lipid metabolism involved in colorectal cancer development, namely of a) farnesyltransferase (Ftase), a cytosolic enzyme that catalyzes the first step in the protein farnesylation; b) farnesyl diphosphate synthase (FPPS, which yields FPP, a substrate for Ftase; c) fatty acid synthase (FAS), an enzyme required for the conversion of acetyl-CoA and malonyl-CoA to palmitate; and d) lipoprotein lipase (LPL), the crucial enzyme for intravascular catabolism of triglyceride-rich lipoproteins. Alterations in the levels of these enzymes may contribute to a cell growth advantage acquired during the carcinogenic process and to the development of malignancy. We have demonstrated an elevated Ftase activity in human colorectal cancer (CRC), with differences in Ftase activity related to histological grading, tumor location and KRAS mutation status. Moreover, the first evidence of FPPS activity in human CRC was demonstrated by our study, where a higher FPPS activity and mRNA expression was present in cancer rather than in normal mucosa. We also detected a hyperactivation of FAS in colon cancer, related to tumor location, sex and, p53 mutation status. Our data reinforce the role of lipid metabolism in the regulation of cellular metabolic processes and in carcinogenesis. Moreover, our findings suggest that biological factors including sex, gene mutation status, as well as the stratification of patients with colorectal cancer into right- and left-sided subsets may be important in patient selection for targeted therapies. Our studies in vitro demonstrated that FAS might also be a molecular target for the antiproliferative activity of olive oil polyphenols in a metabolically defined subset of patients with colon cancer. Moreover, we detected that the serum levels of FAS in patients with colorectal cancer are associated with tumor stage. Recently, we found a significant reduction in the levels of FAS and another lipogenic enzyme, LPL, in adipose tissue adjacent to tumor lesions, compared to the levels of FAS detected in paired tissue distant from neoplasia in patients with colorectal cancer. The study of metabolic changes in lipogenic enzyme pathways, as well as the determination of the distribution of individual roles within each biochemical pathway provide a rationale for selecting a particular reaction step suitable for therapeutic intervention.

Lipoprotein lipase (LPL) is the crucial enzyme for intravascular catabolism of triglyceride-rich lipoproteins. Fatty acid synthase (FAS) is a key anabolic enzyme that catalyzes the terminal steps in the novo biosynthesis of 18:2n-6. The involvement of both LPL and FAS in tumor biology has been widely demonstrated in different studies and to verify whether there are regional differences in the expression of these enzymes in visceral adipose tissue from patients with colorectal cancer might be representative of events which sustain tumor growth. The objective of this study was to evaluate LPL and FAS activity and expression of their genes in adipose tissue adjacent to neoplasia and distant from it from patients operated for colorectal cancer. LPL enzymatic activity was evaluated by a fluorescent method and FAS activity by a radiometer assay. Reverse-transcription and real-time PCR were used to detect mRNA levels of two enzymes. Our findings show a significant reduction in both LPL and FAS gene expression and activity levels in adipose tissue adjacent to tumor lesion compared to those detected in paired tissue distant from neoplasia. These results underline the influence of tumor microenvironment on lipid metabolism in adipose tissue, demonstrating a tumor-induced impairment in the formation and lipid storing capacity of adipose tissue in patients with colorectal cancer.

Background: The leptin receptor is involved in modulating leptin activity, acting as a carrier protein. A link between leptin or leptin receptor and cancer development has been proposed and here, the hypothesis that leptin and its receptor might be implicated in colorectal cancer (CRC) progression and invasion was investigated., Patients and Methods: A total of 71 consecutive patients with CRC were enrolled in the study. Serum leptin and leptin receptor levels were evaluated by commercial ELISA kits., Results: The multinomial logistic regression model showed a positive association of leptin and leptin receptor with advanced tumor stages, which was significant for the leptin receptor in stage IV of disease., Conclusion: High circulating levels of leptin receptor occur in patients with advanced stage of colon cancer, suggesting a role for leptin in cancer progression and aggressiveness.

Background: Myocardial infarction and colorectal cancer are associated at the population level and in autoptic studies. Glycated apolipoprotein B (apoB) is a risk factor for the development of myocardial infarction. The association of glycated apoB with dysplastic and neoplastic colorectal tissue was investigated., Materials and Methods: Forty-eight consecutive surgical specimens, 26 colorectal adenomas and 22 colorectal carcinomas, retrieved from the archives of the Pathologic Anatomy Department of our institution, were examined. The tissue content of glycated apoB was determined using a monoclonal antibody., Results: Glycated apoB was detected in 27% of the adenomas and 45% of the cancer tissue, but only in 18% of the normal tissue near the cancer site., Conclusion: Glycated apoB is associated with dysplastic and even more so with neoplastic cancer tissue.

Aim: To investigate Glyoxalase I and fructosamine-3-kinase (FN3K) activity in red blood cells from patients with colorectal adenomas and cancer., Methods: Thirty three consecutive subjects with one or more histologically confirmed colorectal adenomatous polyps, 16 colorectal cancer patients and a group of 11 control subjects with normal colonoscopy were included in the study. Glyoxalase I and FN3K activities were measured in red blood cells using a spectrophotometric and radiometric assay, respectively., Results: A significant reduction in both Glyoxalase I and FN3K activity was detected in patients with tumors compared to patients with adenomas and the controls. Erythrocyte Glyoxalase I activity in colorectal cancer was approximately 6 times lower than that detected in patients with adenoma (0.022 ± 0.01 mmol/min per milliliter vs 0.128 ± 0.19 mmol/min per milliliter of red blood cells, P = 0.003, Tukey's test). FN3K activity in red blood cells from patients with colon cancer was approximately 2 times lower than that detected in adenoma patients (19.55 ± 6.4 pmol/min per milliliter vs 38.6 ± 31.7 pmol/min per milliliter of red blood cells, P = 0.04, Tukey's test)., Conclusion: These findings suggest that deglycating enzymes may be involved in the malignant transformation of colon mucosa.

Galectin-3 is an endogenous lectin that binds glycan epitopes of cell membrane and some extracellular glycoproteins such as integrins and laminin. Galectin-3 is involved in several biological activities including regulation of cellular cycle, modulation of adhesion and tumor progression and metastasis. 90K/Mac-2BP glycoprotein is also a serum galectin-3 ligand. 90K is able to modulate the immune reaction against tumors and viruses and its level increases in sera of several neoplastic diseases. In our study, we have evaluated levels of both glycoproteins in sera of non metastatic colon cancer patients. Interestingly, galectin-3 ranged higher in cancer patients than in controls (p<0.0001), particularly in more differentiated tumors (p<0.04). Moreover, 90K mean values ranged higher in right-side than in left-side colon cancer. In conclusion, serum galectin3 might represent a useful biomarker to evaluate colon cancer transformation and, together with its ligand 90K, could contribute to the characterization of colon cancer.

Objective: Spontaneous non-enzymatic reaction of protein amino groups with glucose and other reducing sugars, known as glycation or Maillard reaction, has long been considered irreversible and inevitably followed by slow conversion of fructosamines and advanced glycation end products. Instead, recent identification of fructosamine 3 kinase (FN3K) has unveiled that fructosamines can be physiologically repaired, so that the FN3K enzyme could be considered a new form of protein repair., Methods: Thirty-one consecutive patients with colorectal cancer were enrolled in the study. FN3K gene expression was determined using quantitative RT-PCR., Results: The mean level of FN3K gene expression was significantly lower in cancer tissue than in the corresponding normal colorectal mucosa, and FN3K gene was under-expressed most particularly in the tumours located on the left side of the colon., Conclusions: Low mRNA levels of this enzyme in colon cancer tissue with respect to normal surrounding mucosa suggests that neoplastic cells have lost a protective enzymatic system. Reduced FN3K gene expression may be important in the pathogenesis and progression of colorectal cancer., ((c) 2008 S. Karger AG, Basel)

Objective: Fatty acid synthase (FAS) is a multienzyme protein required for the conversion of acetyl coenzyme A and malonyl coenzyme A to palpitate. High levels of FAS expression have been found in many human cancers, including breast, prostate and colon. In this study, we evaluated FAS activity levels and the expression of its mRNA in normal colorectal mucosa and cancer tissue from patients operated for colorectal carcinoma. In addition, the hypothesis of a relation between FAS activity and p53 mutation status of patients was tested., Methods: Forty-two patients were enrolled in the study. FAS activity was measured by using a radiometric assay. FAS gene expression was determined using quantitative reverse-transcription polymerase chain reaction and p53 mutations by polymerase chain reaction single-strand conformation polymorphism., Results: FAS activity levels were significantly higher in cancer than in the corresponding normal mucosa. Tumors located on the left side of the colon showed higher levels of FAS activity and tumors from male patients showed higher FAS activity than tumors from females. No difference was detected in mRNA FAS levels according to tumor side and gender. Moreover, lower levels of FAS activity were detected in patients carrying the p53 mutation., Conclusions: This study suggests that biological factors including sex and gene mutation status, as well as stratification of patients with colorectal cancer into right- and left-sided subsets, may be important in patient selection for targeted therapies and for the subsequent assessment of objective therapeutic responses., (Copyright 2006 S. Karger AG, Basel.)

Background: Alterations in the mevalonate pathway may contribute to malignant cell growth. There are differences in the aetiology, clinical behaviour, pathological and genetic features in cancer of the right versus the left colon. Here, 3-hydroxy-3-methylglutatyl coenzyme A (HMG-CoA) reductase, farnesylpyrophosphate (FPP) synthase and farnesyltransferase (Ftase) activities were measured in human colorectal cancer (CRC) and normal mucosa in order to evaluate their role as potential markers of malignancy, also in relation to cancer location., Patients and Methods: HMG-CoA reductase, FPP synthase and Ftase activities were determined in CRC and normal mucosa of 90 patients by radiochemical assay., Results: The enzymatic activities were higher in cancer than in normal mucosa. The tumours located at the left side showed higher HMG-CoA reductase activity, whereas the right side tumours showed higher levels of Ftase and FPP synthase activity., Conclusion: The determination of mevalonate pathway enzymes in relation to CRC location may be clinically relevant in designing anticancer targeted therapies.

We have investigated the presence of oestrogen receptor-related (ERR) mRNA in human colorectal tumour tissues and adjacent normal mucosa by reverse transcriptase and nested-polymerase chain reaction. ERRalpha was found in 100% of the patients and ERRgamma in approximately 30% while ERRbeta was not detected at all. The multiplex PCR analysis showed elevated levels of ERRalpha mRNA in tumour tissue compartment as compared to normal mucosa, whereas ERRgamma mRNA was found in lower levels but in both tissue compartments. In contrast, oestrogen receptor (ERalpha and ERbeta) mRNA levels were shown to be decreased in tumour tissues. A positive correlation was observed between ERalpha and ERbeta and between ERalpha and ERRalpha, respectively, in normal mucosa but not in tumour tissue. ERRalpha expression in tumour tissues significantly increased from TNM stages II to IV, whereas both ERs progressively declined. These findings suggest that ERRalpha, as well as the two ERs, might play a critical role in the progression of the colorectal cancer.

Objective: In this study, the serum lipid profile, including total cholesterol (TC), triglycerides (TG), high-density (HDL-C) and low-density lipoprotein cholesterol (LDL-C), has been investigated in colorectal cancer patients (CRC) with and without synchronous distant metastases. The aim of this study was to verify whether the presence of metastases was associated to serum lipid abnormalities, and whether lipoprotein abnormalities were linked to the nutritional status., Methods: The fasting serum lipid profile was examined in 84 CRC patients using colorimetric methods. To determine the nutritional status, the body mass index (BMI) was calculated and serum albumin was measured., Results: Patients with distant metastases showed significantly higher levels of TC, LDL-C and the LDL-C/HDL-C ratio than patients without metastases (p< 0.05). The presence of metastases was positively associated with TC, LDL-C and the LDL-C/HDL-C ratio, being independent of sex, age and BMI., Conclusions: Elevated serum lipid levels may facilitate the development of distant metastasis in CRC patients., ((c) 2005 S. Karger AG, Basel.)

Background: Polyamines are important polycations found in high concentrations in gastrointestinal neoplasms, and ornithine decarboxylase is the key enzyme in their biosynthesis. Also genes with oncogenic potential (e.g. K-ras and p53) contribute to neoplastic transformation by modifying normal cellular proliferation and differentiation. Our aim was to evaluate the ornithine decarboxylase activity and polyamine levels in samples of colorectal carcinoma and uninvolved surrounding mucosa from 86 patients (52 men and 34 women) showing different patterns of K-ras/p53 mutations., Methods: Polyamines were evaluated by high performance liquid chromatography. Ornithine decarboxylase activity was determined using the radiometric method. K-ras and p53 mutations were investigated by PCR followed by restriction fragment length polymorphism (PCR-RFLP) and single strand conformational polymorphism (PCR-SSCP), respectively. Multiple linear regression analysis was used to analyse relationships among polyamine biosynthesis, clinical-pathological variables and K-ras/p53 mutations., Results: ODC activity and polyamine levels were significantly higher in neoplastic samples than in normal surrounding mucosa. K-ras codon 12 mutation was found in 25/86 patients (29.1%) and p53 gene mutation in 41/86 (47.7%). Polyamine biosynthesis was significantly higher in cancers showing K-ras mutation, either with or without p53 mutation [K-ras(+)/p53(-) and K-ras(+)/p53(+)], compared to samples with K-ras wild type [K-ras(-)/p53(-) and K-ras(-)/p53(+)]. Multiple linear regression analysis confirmed this finding., Conclusions: The present study provides evidence of a close relationship between K-ras mutation and polyamine biosynthesis in human colorectal carcinoma in a way that is largely p53 independent. In addition, our data support the hypothesis of different pathways in colorectal tumorigenesis reflecting different combinations of biochemical parameters and genetic alterations.

Objective: Farnesyl diphosphate synthase (FPPs) produces FPP which is considered a branch-point intermediate in the synthesis of sterols and isoprenylated cellular metabolites. In this study we investigated whether detectable FPPs activity was present in human colorectal cancer (CRC), also evaluating in vitro the role of this enzyme in the growth and apoptosis of CRC cells by using Pamidronate (PAM), a FPPs activity inhibitor., Methods: The activity level of FPPs was determined in CRC and the normal surrounding mucosa of 50 patients by radiochemical assay. The FPPs mRNA expression was investigated in 15 of 50 patients by quantitative reverse transcriptase polymerase chain reaction (RT-PCR). K-ras mutation was evaluated using PCR and restriction enzyme analysis. Cell growth and apoptosis, after PAM treatment, in human CRC cell line DLD-1 were measured by MTT test and DNA fragmentation, respectively., Results: FPPs activity was detectable in human CRC. FPPs activity and its mRNA were significantly more abundant in cancer samples than in normal mucosa. In vitro PAM resulted in a significant reduction of cell growth and also gave rise to a marked proapoptotic effect., Conclusions: This study provides the first evidence of the presence of FPPs activity in human CRC. Moreover, FPPs enzyme was found to play a significant role in colon cancer proliferation., (Copyright (c) 2004 S. Karger AG, Basel)

A distinct genetic pathway may be involved in the development of polypoid and flat colorectal cancers, two morphologically different cancer subtypes. The present study was undertaken to clarify whether different combinations of some genetic alterations commonly involved (such as K-ras and p53 gene mutations) may exist between polypoid and flat types. In addition, to investigate any different proliferative behavior between the two distinct types of colorectal cancer, we tested the enzymatic activity of ornithine decarboxylase (ODC). A total of 29 polypoid type and 21 flat type colorectal cancers were selected for this study. We investigated K-ras and p53 mutations by polymerase chain reaction followed by restriction fragment length polymorphism (PCR-RFLP) and single strand conformational polymorphism (PCR-SSCP) analysis, respectively. A radiometric method was used to evaluate ODC activity. K-ras and p53 gene mutations were present in 30 and 48% of cases, respectively. A significant association between the p53 mutation and the flat type of colorectal cancer was detected; on the contrary, no significant difference in frequency of K-ras mutation between polypoid and flat type colorectal cancer was found. A statistically significant difference in ODC activity levels was observed between polypoid and flat types. Moreover, we found that ODC activity was significantly higher in neoplastic tissue than in surrounding normal mucosa in polypoid type colorectal cancer. Different mutation patterns and proliferative behavior were observed in polypoid and flat colorectal malignant tumors. Further studies will be required to ascertain whether the distinct growth appearance of colorectal cancer can affect the outcome and prognosis of patients with this type of malignant disease.

Background: The enzyme farnesyltransferase has emerged as an important target for anti-cancer therapies. Farnesyltransferase inhibitors have been introduced in clinical trials of subjects with colorectal cancer. We investigated Farnesyltransferase activity, beta-subunit Farnesyltransferase protein expression and its mRNA in patients with colorectal cancer and its relationship with clinicopathological features and K-ras mutation., Methods: Farnesyltransferase activity was determined by Farnesyltransferase [3H] SPA enzyme assay. Beta-subunit Farnesyltransferase protein expression was investigated by Western blotting and its mRNA by reverse transcriptase-polymerase chain reaction. K-ras mutation was detected by polymerase chain reaction amplification and restriction enzyme analysis. Multiple linear regression analysis was used to analyse relationships among age, sex, site of tumour, Dukes' stage, histological differentiation, K-ras mutation and Farnesyltransferase activity in normal mucosa and cancer., Results: The levels of Farnesyltransferase activity and beta-subunit Farnesyltransferase protein expression were significantly higher in cancer than in normal mucosa. Moreover, tumours located on the right side, with mucinous histological differentiation and with K-ras mutation showed higher levels of Farnesyltransferase activity., Conclusions: Our findings suggest that Farnesyltransferase activity may be a potential marker of tumourigenicity. The differences in Farnesyltransferase activity in relation to histological grading, tumour location and K-ras mutation described here may constitute a starting point for investigating the causes of this variation within the large bowel.

Background: We have previously show that, 63.3% of colorectal cancers did not express the Low Density Lipoprotein Receptor (LDLR). We now report the findings of a study on the expression of LDLR and its mRNA in neoplastic tissue specimens of human colorectal cancer (CRC), carried out to verify whether the absence of the LDLR in these tumours is reflected by the absence of its transcript., Materials and Methods: 32 patients (10 females and 22 males) operated for CRC were included in the study. The LDLR levels were evaluated by immunoenzymatic assay. The LDLR-mRNA, reverse-transcribed and then amplified by polymerase chain reaction, was detected by chromatography., Results: The LDLR protein was present in 12 out of the 32 patients. LDLR-mRNA expression was detected in 17 out of the 32 patients. The absence of the LDLR protein was reflected by the absence of its transcript in 13 out of the 20 tumours; The LDLR mRNA levels were significantly higher in the tumours that did not expres LDLR., Conclusion: The variable expression of the LDLR protein and LDLR mRNA in CRC detected in this study suggests the possibility that different therapeutic strategies may be indicated for these tumours.

Background: We have previously shown that 63.3% of colorectal cancer neoplastic specimens did not express the Low Density Lipoprotein Receptor (LDLR) protein and that the absence of LDLR predicted shorter survival. We now report the findings of a preliminary study on HMG-CoA reductase (HMG-CoAR) activity in neoplastic tissue specimens of human colorectal cancers (CRC) expressing or not expressing LDLR., Materials and Methods: The tissue specimens were obtained from 16 patients (10 males and 6 females) undergoing surgical resection for CRC, and previously characterized for LDLR (7 not expressing LDLR and 9 expressing LDLR). HMG-CoAR activity was measured by radiochemical assay using 14C-HMG-CoA as substrate., Results: HMG-CoAR activity was significantly higher in specimens not expressing LDLR than in those expressing LDLR [8.3 pmol/min/mg prot (2.4-16) vs 3.9 pmol/min/mg prot (1.2-7.8), data expressed as median value and the range, p = 0.02, Wilcoxon Rank sum test)]., Conclusions: The cholesterol requirement in CRC not expressing LDLR may be met by increasing endogenous synthesis. For this reason, the use of HMG-CoA R inhibitors for the treatment of CRC expressing high HMG-CoAR activity-dependence for growth may be clinically important.

Cancer cells require more cholesterol than normal cells. This requirement seems to be satisfied by a higher HMG-CoA reductase activity or a higher activity of low density lipoprotein receptor (LDLR). We investigated the prognostic value of LDLR in colorectal carcinoma (CRC) patients. The LDLR was evaluated in 90 patients with CRC by ELISA. The survival time and the relative risk of prognostic factors were analyzed by Kaplan-Meier estimates and Cox proportional hazard model. Thirty three cases were LDLR positive (+), while 57 LDLR negative (-). The survival of LDLR(-) patients was shorter than that of LDLR(+). By Cox model, the absence of LDLR and time until metastasis resulted significantly associated with the CRC-related survival. The absence of LDLR in CRC predicts a shorter survival.

The over-expression of epidermal growth factor receptor (EGF-R), EGF and transforming growth factor alpha (TGFalpha) could be a mechanism for colorectal tumor cells to escape normal growth controls. Our aims were: (i) to evaluate EGF, TGFalpha, and EGF-R concentrations in neoplastic tissue and surrounding mucosa from 40 patients with colorectal adenocarcinoma, and (ii) to assess the expression of these growth factors and their receptor in relation to the tumor site. EGF, TGFalpha, and EGF-R were detected in either colorectal neoplastic tissue or surrounding mucosa. Significantly increased levels of EGF and EGF-R were present in neoplastic samples compared to surrounding mucosa. Furthermore, a significant increase in TGFalpha and in EGF levels was observed in the left-sided surrounding mucosa and left-sided neoplastic tissue, respectively. EGF-R stimulation by its ligands may play an important role in colorectal neoplastic tissue. Moreover, the higher content of growth factors in the left-side than the right-side colon suggests different growth properties in the proximal and distal colon.

The low density lipoprotein receptor (LDLR) is a cell surface protein that binds with LDL, providing the cell with cholesterol for new membrane synthesis. Rapidly growing cells have high numbers of LDLRs, and these proteins have also been detected in neoplastic samples of human colorectal mucosa. Polyamines, putrescine, spermidine, and spermine, play an important role in cellular growth, and studies on colorectal cancers have demonstrated higher polyamine levels in neoplastic mucosa samples than in surrounding mucosa. The aim of this study was to investigate LDLR and polyamine levels in the neoplastic tissue of 43 patients (28 males and 15 females) with colorectal adenocarcinoma, using enzymatic immunoassay and high performance liquid chromatography, respectively. Specimens of neoplastic mucosa were considered LDLR-positive or LDLR-negative when the amount of bound human anti-LDLR antibody detected was equal or higher or lower than the cut-off value (0.5 ng of bound anti-LDLR Ab/mg protein), respectively. Twenty-one subjects were LDLR-positive and 22 LDLR-negative. Polyamine levels (nmol/g tissue) were higher in LDLR-positive specimens; this increase was significant for total polyamines (P < 0.05). These findings, reporting the presence of increased polyamine content in LDLR-positive colorectal neoplastic specimens, suggest an association between LDLR levels and gastrointestinal neoplastic proliferative activity.

In order to verify the presence of Low Density Lipoprotein Receptor (LDLR) in cellular membranes isolated from human colonic tissue, samples from the neoplastic colorectum and the normal surrounding mucosa were studied by an enzyme-linked-immunosorbent assay. A monoclonal antibody against the human LDLR was used. The LDLR content revealed a considerable inter-individual variation. In 36 out of 53 cases (68%) there was no LDLR presence in either normal or neoplastic tissue samples. In 5 out of 53 cases (9.4%), LDLRs were detected in both types of tissue samples, in 9 cases out of 53 (17%) LDLRs were present in neoplastic tissue, while in 3 out of 53 cases (5.6%) only in normal mucosa. The anti-LDLR mono-clonal antibody (mAb) binding was significantly higher in neoplastic tissue samples than normal surrounding colonic mucosa ones. Sex, age, body mass index (BMI), serum cholesterol, tumour site, histologic grading and Dukes' stage did not seem to be associated with LDLR presence.