RESUMEN
OBJECTIVE: To use cytoplasmic tissue extract as a new specimen source to quantify transforming growth factor beta 1 (TGFbeta1) protein in metastatic axillary lymph node tissue (ALNT) of breast cancer (BC) patients and to confirm the feasibility of this approach in a prospective pilot study on a subgroup of patients with invasive BC. STUDY DESIGN: The 6 selected malignant and autologous nonmalignant pairs of ALNT were fractionated, under special preanalytical, nonaggressive/nondenaturing conditions, to obtain respective cytoplasmic extracts for TGFbeta1 detection by the Quantikine (R&D Systems Inc., Minneapolis, Minnesota, U.S.A.) enzyme-linked immunosorbent assay kit. RESULTS: The data indicated a highly significant (r = 0.973054) positive linear correlation between the TGFbeta1 concentration and total protein concentration in cytoplasmic extract of metastatic ALNT. The subsequent patients' pilot study, performed strictly before any clinicopathologic factors were accessible, revealed significantly (p < 0.01) elevated TGFbeta1 in malignant ALNT (median value: 1.05 ng/mg protein, range: 0.67-3.6 ng/mg protein, n = 6) vs. autologous nonmalignant ALNT controls (median value: 0.48 ng/mg protein, range: 0.29-0.90 ng/mg protein, n = 6). This elevation was correlated with the number of metastatic axillary lymph nodes with respect to the total and was consistent with an increase in size of tumor deposits in axillary lymph nodes. CONCLUSION: Our data provide for the first time suggestive evidence that the TGFbeta1 level in cytoplasmic extracts of metastatic ALNTs may be a promising biomarker of invasiveness for BC patients. Confirmatory, large-scale studies are needed to evaluate possible implications of this putative biomarker in BC diagnosis and treatment.
Asunto(s)
Adenocarcinoma/metabolismo , Neoplasias de la Mama/metabolismo , Ganglios Linfáticos/metabolismo , Factor de Crecimiento Transformador beta1/metabolismo , Adenocarcinoma/secundario , Adulto , Anciano , Axila , Neoplasias de la Mama/patología , Fraccionamiento Celular , Femenino , Humanos , Metástasis Linfática , Persona de Mediana Edad , Invasividad NeoplásicaRESUMEN
Tiazofurin (TZF) is a cytostatic drug that leads to depletion of the GTP pool in tumor and normal cells via its active metabolite tiazofurin-adenine dinucleotide (TAD). TAD was detected in different cell lines, but not in erythrocytes, so the mechanism of erythrocytotoxicity of TZF remains unclear. The purpose of this study was to evaluate in vitro and in vivo action of tiazofurin on rat erythrocytes (RBC). After two decades of clinical trials the question of erythrocytotoxicity of TZF had remained unexplained making this study justified. Since we have previously demonstrated early erythrocytotoxic effects in male Wistar rats, we extend this finding on isolated RBC. Isolated erythrocytes from untreated animals were treated in buffered solution or plasma containing TZF. In addition, groups of 10 rats were treated with 200 and 1000 mg/kg of TZF and hematologic parameters were analyzed by flowcytometry and by the analysis of the peripheral blood smears. Early signs of hemolysis or aberrant structures were monitored by scanning probe microscopy (SPM). We suggest that correlation exists between early erythrocytotoxicity and irregularities in erythrocyte morphology and membrane integrity. We also found that TZF affects responsiveness to oxidative stress. This is in concordance with flowcytometric findings describing anisocytosis and anisochromosis of RBC.