Silver(I)/6-hydroxyiminolumazine compounds differently modify renin-angiotensin system-regulating aminopeptidases A and N in human neuroblastoma and glioma cells.

We have described that local tissue renin-angiotensin-system (RAS) is involved in tumor growth in a rat model of experimental glioma in vivo, through the modification of their corresponding local proteolytic regulatory enzymes. Thus, we have found a time-dependent significant decrease in aminopeptidase N (APN) and a significant increase in aminopeptidase A (APA) activities concomitantly with tumor growth in tumor tissue whereas no changes were found in circulating aminopeptidase activities; we suggested that angiotensin peptides may play an essential step in both tumor infiltration and associated angiogenesis. Here we analyze in vitro the antiproliferative efficacy, apoptotic properties and effects of three new disilver complexes containing E-6-(hydroxyimino)ethyl-1,3,7-trimethyllumazine (lumazine=pteridine-2,4(1H,3H)-dione) on RAS-regulating APA and APN specific activities in human neuroblastoma and glioma cell lines NB69 and U373-MG. Disilver compounds showed cytotoxicity against both cell lines, although their potency was different for each cell type. Furthermore, NB69 cells need higher concentrations of silver complexes than U373-MG cells to obtain a 50% growth inhibition. All compounds showed apoptotic effects, with U373-MG cells being more susceptible. The three silver complexes tested also show a dose-dependent inhibitory effect on APA activity in NB69 and U373-MG cells, although U373-MG cells are more sensitive. On the contrary, none of them showed effects on APN activity in NB69 neuroblastoma cells whereas the three compounds showed a dose-dependent stimulatory effect on APN activity in U373-MG glioma cells with a similar potency. Disilver complexes show specific antitumor activity against brain tumor cells acting through the paracrine regulating system mediated by local tissue RAS.

Caspase induction and BCL2 inhibition in human adipose tissue: a potential relationship with insulin signaling alteration.

OBJECTIVE: Cell death determines the onset of obesity and associated insulin resistance. Here, we analyze the relationship among obesity, adipose tissue apoptosis, and insulin signaling. RESEARCH DESIGN AND METHODS: The expression levels of initiator (CASP8/9) and effector (CASP3/7) caspases as well as antiapoptotic B-cell lymphoma (BCL)2 and inflammatory markers were assessed in visceral (VAT) and subcutaneous (SAT) adipose tissue from patients with different degrees of obesity and without insulin resistance or diabetes. Adipose tissue explants from lean subjects were cultured with TNF-α or IL-6, and the expression of apoptotic and insulin signaling components was analyzed and compared with basal expression levels in morbidly obese subjects. RESULTS: SAT and VAT exhibited increased CASP3/7 and CASP8/9 expression levels and decreased BCL2 expression with BMI increase. These changes were accompanied by increased inflammatory cytokine mRNA levels and macrophage infiltration markers. In obese subjects, CASP3/7 activation and BCL2 downregulation correlated with the IRS-1/2-expression levels. Expression levels of caspases, BCL2, p21, p53, IRS-1/2, GLUT4, protein tyrosine phosphatase 1B, and leukocyte antigen-related phosphatase in TNF-α- or IL-6-treated explants from lean subjects were comparable with those found in adipose tissue samples from morbidly obese subjects. These insulin component expression levels were reverted with CASP3/7 inhibition in these TNF-α- or IL-6-treated explants. CONCLUSIONS: Body fat mass increase is associated with CASP3/7 and BCL2 expression in adipose tissue. Moreover, this proapoptotic state correlated with insulin signaling, suggesting its potential contribution to the development of insulin resistance.

Eficacia de la biopsia intraoperatoria del ganglio centinela mediante el método one step nucleic acid amplification para evitar la linfadenectomía axilar en mujeres con cáncer de mama tratadas previamente con quimioterapia neoadyuvante / Effectiveness of intra-operative sentinel node biopsy by one-step nucleic acid amplification to avoid axillary lymphadenectomy in women with breast cancer treated with neoadjuvant chemotherapy

Objetivos. Evaluar en pacientes con ganglios axilares clínicamente negativos de inicio, la efectividad de la biopsia selectiva del ganglio centinela (BSGC) intraoperatoria mediante el método one step nucleic acid amplification (OSNA) para detectar metástasis microscópicas o celulares tras quimioterapia neoadyuvante, y evitar la duplicidad de procedimientos quirúrgicos. Pacientes y métodos. Se evaluó la efectividad de la BSGC mediante OSNA en pacientes con cáncer de mama que previamente tenían una axila clínica y ecográficamente negativa tras quimioterapia neoadyuvante (44 pacientes) o antes de la quimioterapia neoadyuvante (33 pacientes). Resultados. La tasa de identificación del ganglio centinela (GC) fue del 100% en ambos grupos. En las pacientes con BSGC previa a la quimioterapia se detectaron 13 mujeres con ganglios positivos (11 macrometástasis y 2 micrometástasis). En las pacientes tratadas primero con quimioterapia, se detectaron 10 mujeres con GC positivos, que fueron todos macrometástasis. El valor predictivo negativo de la prueba de ultrasonidos fue del 60,6% en pacientes con BSGC previa a quimioterapia y del 77,3% en pacientes con quimioterapia y posterior BSGC. Conclusiones. La BSGC mediante el método OSNA en mujeres que presentan clínicamente ganglios linfáticos negativos tras haber recibido quimioterapia neoadyuvante predice el estado axilar con gran precisión. Permite de forma inmediata tomar decisiones sobre la indicación o no de realizar una linfadenectomía axilar, evitando así el retraso en la administración de la quimioterapia y beneficiándose las pacientes de un solo procedimiento quirúrgico(AU)

Objectives. To evaluate in patients with clinically negative axillary nodes at initial presentation, the effectiveness of sentinel lymph node biopsy (SLNB) using intraoperative the one step nucleic acid amplification (OSNA) method to detect microscopic metastases or isolated tumor cells after neoadjuvant chemotherapy. Thus, axillary dissection and duplication of surgical procedures will be avoided. Patients and methods. We evaluated in patients with breast cancer and clinically negative axilla, the effectiveness of SLNB by OSNA after neoadjuvant chemotherapy (44 patients) or prior to neoadjuvant chemotherapy (33 patients). Results. The rate of SLN identification was 100% in both groups. In patients with SLNB prior to systemic treatment, 13 women showed positive nodes (11 macrometastases and 2 micrometastases), and those with SLNB after neoadjuvant chemotherapy, positive SLNB were detected in 10 women, which were all of them macrometastases. The negative predictive value of ultrasonography was 60.6% in patients with SLNB prior to neoadjuvant therapy and 77.3% in patients with chemotherapy followed by SLNB. Conclusions. Intraoperative SLNB using OSNA in women with clinically negative axillary lymph nodes at initial presentation who received neoadjuvant chemotherapy, predicts axillary status with high accuracy. Also it allows immediately make decisions about the indication or not to perform an axillary dissection, thus avoiding delay in the administration of chemotherapy and benefit the patients for a single surgical procedure(AU)