Begoña Sanz

Biosorption of heavy metals to immobilised Phormidium laminosum biomass

The capacity to biosorb Cu(II), Fe(II), Ni(II) and Zn(II) by non-viable biomass of the cyanobacterium Phormidium laminosum entrapped in polysulfone and epoxy resin beads was investigated. The biosorption process depended on the wetting of biomass beads, the rate of metal biosorption decreasing when dry biomass beads were used. A decrease in the immobilised biomass bead size led to an increase in the rate of metal biosorption. The amount of metal biosorbed increased with the biomass and the amount of metal available. The biosorbed metal was completely desorbed from the biomass beads by washing with 0.1 M HCl. Polysulfone biomass beads can be reused for, at least, ten consecutive biosorption/desorption cycles without apparent loss of efficiency after its reconditioning with 0.1 M NaOH.

The impact of peptidase activity on clear cell renal cell carcinoma survival

Several studies have proposed that protease expression and activity may have a predictive value in the survival of clear cell renal cell carcinoma (CCRCC). Most efforts on this issue have been focused on the analysis of matrix metalloproteinases (MMP) and very little on the role of other proteases, such as peptidases. The catalytic activity of 9 peptidases (APN, APB, ASP, CAP, DPP-IV, NEP/CD10, PEP, PGI, and PSA) was quantified by fluorometric methods in a series of 79 CCRCC patients, and the results obtained were analyzed for survival (Kaplan-Meier curves, log-rank test, and Cox multivariate analysis). CCRCC patients with higher activity levels of membrane-bound APN and soluble APN, DPP-IV, and CAP had significantly shorter 5-yr survival rates than those with lower levels. By contrast, higher soluble APB activity significantly correlated with longer survival. Our data suggest the involvement of peptidases in the biological aggressiveness of CCRCC and support the usefulness of measuring these proteases to assess the prognosis of patients with CCRCC.

Cannabinoid CB1 Receptor Is Downregulated in Clear Cell Renal Cell Carcinoma

Several studies in cell cultures and in animal models have demonstrated that cannabinoids have important antitumoral properties. Because many of these effects are mediated through cannabinoid (CB) receptors CB1 and CB2, the study of their expression in human neoplasms has become of great interest in recent years. Fresh and formalin-fixed tissue samples of 20 consecutive clear cell renal cell carcinomas (CCRCCs) were collected prospectively and analyzed for the expression of both CB receptors by using RT–PCR, Western blot (WB), and immunohistochemical techniques. RT-PCR assays demonstrated the expression of mRNA encoding the CB1 in tumor tissue and in adjacent non-neoplastic kidney. Conversely, WB and IHC revealed a marked downregulation of CB1 protein in tumor tissue; CB2 was not expressed. The obtained data suggest a possible implication of the endocannabinoid system in renal carcinogenesis. A posttranscriptional downregulation of CB1 and the absence of expression of CB2 characterize CCRCC. (J Histochem Cytochem 58:1129–1134, 2010)

Dipeptidyl-Peptidase IV Activity Is Correlated with Colorectal Cancer Prognosis

Background Dipeptidyl-peptidase IV (EC 3.4.14.5) (DPPIV) is a serine peptidase involved in cell differentiation, adhesion, immune modulation and apoptosis, functions that control neoplastic transformation. Previous studies have demonstrated altered expression and activity of tissue and circulating DPPIV in several cancers and proposed its potential usefulness for early diagnosis in colorectal cancer (CRC). Methods and principal findings The activity and mRNA and protein expression of DPPIV was prospectively analyzed in adenocarcinomas, adenomas, uninvolved colorectal mucosa and plasma from 116 CRC patients by fluorimetric, quantitative RT-PCR and immunohistochemical methods. Results were correlated with the most important classic pathological data related to aggressiveness and with 5-year survival rates. Results showed that: 1) mRNA levels and activity of DPPIV increased in colorectal neoplasms (Kruskal-Wallis test, p<0.01); 2) Both adenomas and CRCs displayed positive cytoplasmic immunostaining with luminal membrane reinforcement; 3) Plasmatic DPPIV activity was lower in CRC patients than in healthy subjects (Mann-U test, p<0.01); 4) Plasmatic DPPIV activity was associated with worse overall and disease-free survivals (log-rank p<0.01, Cox analysis p<0.01). Conclusion/significance 1) Up-regulation of DPPIV in colorectal tumors suggests a role for this enzyme in the neoplastic transformation of colorectal tissues. This finding opens the possibility for new therapeutic targets in these patients. 2) Plasmatic DPPIV is an independent prognostic factor in survival of CRC patients. The determination of DPPIV activity levels in the plasma may be a safe, minimally invasive and inexpensive way to define the aggressiveness of CRC in daily practice.

Angiotensin-converting enzymes (ACE and ACE2) are downregulated in renal tumors

The angiotensin-converting enzymes (ACE and ACE2) are highly expressed in renal tubules and play an important role in the regulation of renal function by the intrarenal renin-angiotensin system (iRAS). Dysregulation of these cell-surface peptidases has been associated with renal injury. Most of these studies, however, have focused on non-neoplastic kidney diseases. In the present study, ACE and ACE2 activity and protein and mRNA expression were analysed in a subset of clear-cell (CCRCC) and chromophobe (ChRCC) renal cell carcinomas, and in renal oncocytoma (RO). Enzyme activity was measured by spectrofluorometric (ACE2) and spectrophotometric assays (ACE), and protein and mRNA expression were determined by immunohistochemistry and qRT-PCR assays, respectively. The enzyme activities and immunohistochemistry showed that both enzymes are mainly downregulated in these neoplasms. qRT-PCR studies in CCRCC showed no positive correlation between ACE and ACE2 activity/protein expression and mRNA levels, whereas downregulation of ACE2 mRNA levels was observed in tumors from the distal nephron (ChRCC and RO). These findings suggest a metabolic imbalance in iRAS and a role of this system in renal neoplastic diseases, and point to ACE and ACE2 as potential prognostic/diagnostic markers.

Cannabinoid CB1 receptor is expressed in chromophobe renal cell carcinoma and renal oncocytoma

OBJECTIVE To analyze the mRNA and protein expression of cannabinoid receptors CB1 and CB2 in chromophobe renal cell carcinoma (ChRCC) and renal oncocytoma (RO). DESIGN AND METHODS Fresh and formalin-fixed tissue samples of ChRCC and RO were analyzed by using real-time quantitative RT-PCR and immunohistochemical techniques (n=40). RESULTS Quantitative RT-PCR analysis showed that CB1 mRNA was underexpressed by 12-fold in ChRCC and had a variable expression in RO. CB1 protein showed intense positive immunostaining in both neoplasms. Both CB2 mRNA and protein were not expressed in tumor and non tumor renal tissue. CONCLUSION This distinct immunoprofile may eventually be used as an additional tool with practical interest in the differential diagnosis of renal tumors.

Prolyl Endopeptidase Activity Is Correlated with Colorectal Cancer Prognosis

Background and Objective: Prolyl endopeptidase (PEP) (EC 3.4.21.26) is a serine peptidase involved in differentiation, development and proliferation processes of several tissues. Recent studies have demonstrated the increased expression and activity of this cytosolic enzyme in colorectal cancer (CRC). However, there are no available data about the impact of this peptidase in the biological aggressiveness of this tumor in patient survival. Methods: The activity of PEP in tissue (n=80) and plasma (n=40) of patients with CRC was prospectively analyzed by fluorimetric methods. Results were correlated with the most important classic pathological data related to aggressiveness, with 5-year survival rates and other clinical variables. Results: 1) PEP is more active in early phases of CRC; 2) Lower levels of the enzyme in tumors were located in the rectum and this decrease could be related with preoperative chemo-radiotherapy; 3) PEP activity in tissue was higher in patients with better overall and disease-free survival (log-rank p<0.01, Cox analysis p<0.01); 4) Plasmatic PEP activity was significantly higher in CRC patients than in healthy individuals and this was associated with distant metastases and with worse overall and disease-free survivals (log-rank p<0.05, Cox analysis p<0.05). Conclusions: PEP activity in tissue and plasma from CRC patients is an independent prognostic factor in survival. The determination of PEP activity in the plasma may be a safe, minimally invasive and inexpensive way to define the aggressiveness of CRC in daily practice.

Altered activity and expression of cytosolic peptidases in colorectal cancer

Background and Objective: The role of peptidases in carcinogenic processes and their potential usefulness as tumor markers in colorectal cancer (CRC) have been classically attributed to cell-surface enzymes. The objective of the present study was to analyze the activity and mRNA expression of three cytosolic peptidases in the CRC and to correlate the obtained results with classic histopathological parameters for tumor prognosis and survival. Methods: The activity and mRNA levels of puromycin-sensitive aminopeptidase (PSA), aminopeptidase B (APB) and pyroglutamyl-peptidase I (PGI) were measured by fluorimetric and quantitative RT-PCR methods in colorectal mucosa and tumor tissues and plasma samples from CRC patients (n=81). Results: 1) PSA and APB activity was higher in adenomas and carcinomas than in the uninvolved mucosa. 2) mRNA levels of PSA and PGI was lower in tumors. 3) PGI activity in CRC tissue correlated negatively with histological grade, tumor size and 5-year overall suvival of CRC patients. 4) Higher plasmatic APB activity was independently associated with better 5-year overall survival. Conclusions: Data suggest that cytosolic peptidases may be involved in colorectal carcinogenesis and point to the determination of this enzymes as a valuable method in the determination of CRC prognosis.

Altered Peptidase Activities in Thyroid Neoplasia and Hyperplasia

Background. Papillary thyroid carcinoma (PTC), follicular thyroid adenoma (FTA), and thyroid nodular hyperplasia (TNH) are the most frequent diseases of the thyroid gland. Previous studies described the involvement of dipeptidyl-peptidase IV (DPPIV/CD26) in the development of thyroid neoplasia and proposed it as an additional tool in the diagnosis/prognosis of these diseases. However, very little is known about the involvement of other peptidases in neoplastic and hyperplastic processes of this gland. Methods. The catalytic activity of 10 peptidases in a series of 30 PTC, 10 FTA, and 14 TNH was measured fluorimetrically in tumour and nontumour adjacent tissues. Results. The activity of DPPIV/CD26 was markedly higher in PTC than in FTA, TNH, and nontumour tissues. Aspartyl aminopeptidase (AspAP), alanyl aminopeptidase (AlaAP), prolyl endopeptidase, pyroglutamyl peptidase I, and aminopeptidase B activities were significantly increased in thyroid neoplasms when compared to nontumour tissues. AspAP and AlaAP activities were also significantly higher in PTC than in FTA and TNH. Conclusions. These data suggest the involvement of DPPIV/CD26 and some cytosolic peptidases in the neoplastic development of PTC and FTA. Further studies will help to define the possible clinical usefulness of AlaAP and AspAP in the diagnosis/prognosis of thyroid neoplasms.

Aminopeptidase N Activity Predicts 5-Year Survival in Colorectal Cancer Patients

Background Aminopeptidase N (APN; EC 3.4.11.2) is a membrane dimeric metallopeptidase involved in differentiation, development, and proliferative processes of several tissues. Recent studies have demonstrated the increased expression and activity of this enzyme in several cancers. However, there are no available data about the impact of this peptidase in the biological aggressiveness and the survival of colorectal cancer (CRC) patients. Methods The activity and mRNA expression of APN in tumor tissue (n = 81) and plasma (n = 40) of patients with CRC of low and high grades and stages were prospectively analyzed by fluorimetric and quantitative reverse transcriptase–polymerase chain reaction methods. Data obtained in adenoma and CRC were compared with those from the surrounding normal mucosa. Classic clinical and pathological parameters were stratified following APN data and analyzed for 5-year survival. Results mRNA levels of APN (ANPEP) were lower in colorectal adenomas and adenocarcinomas than in the surrounding uninvolved mucosa (Kruskal-Wallis, P < 0.001). Aminopeptidase N activity in CRC tissue was higher in patients with better overall survival (log-rank P < 0.05, Cox analysis P < 0.05). By contrast, higher plasmatic APN activity correlated with worse overall survival (log-rank P < 0.01, Cox analysis P < 0.05). Conclusions Aminopeptidase N activity in tissue and plasma from CRC patients is an independent prognostic factor of 5-year survival. The determination of APN activity levels in the plasma may be a safe, minimally invasive, and inexpensive way to define the aggressiveness of CRC in daily practice.