Non-metastatic Mammary Adenocarcinoma Research Articles

Rb localization and phosphorylation kinetics correlate with the cellular phenotype of cultured breast adenocarcinoma cells.

Retinoblastoma protein (Rb) expression has been correlated with state of differentiation, proliferation rate, and metastatic potential in breast adenocarcinomas and established cell lines. These observations, based on immunoreactivity of total Rb rather than hypophosphorylated protein, do not address the relationship between functional Rb and indicators of an aggressive transformed cellular phenotype. We hypothesized that the distribution of functional Rb and the kinetics of Rb phosphorylation would differ between cell lines representing immortalized mammary epithelium (MCF10A), differentiated nonmetastatic mammary adenocarcinoma (MCF-7), and poorly differentiated, highly metastatic mammary adenocarcinoma (MDA-MB-231) and that these differences would be informative of the cellular phenotype. Direct immunofluorescence microscopy was used to compare qualitatively the subcellular localization of total and hypophosphorylated Rb protein in synchronized and asynchronous cells. This technique was also used to quantitatively assess the amounts of hypophosphorylated Rb throughout the cell cycle in these representative cell lines. Total Rb stained more prominently than hypophosphorylated Rb in the nucleus of all asynchronous cells. Rb phosphorylation was more rapid in MCF-7 cells than in MCF10A cells, whereas Rb dephosphorylation appeared deregulated in MDA-MB-231 cells. We conclude that assessment of hypophosphorylated Rb may be more useful than assessment of total Rb for the evaluation of transformed breast adenocarcinoma phenotypes.

Effects of metastatic and non-metastatic mammary adenocarcinoma on tissue distribution of gallium-67 in the rat

The purpose of this work was to study the effect of metastatic and non-metastatic mammary adenocarcinoma on tissue distribution of gallium-67 (67 Ga) citrate in Fischer-344 female rats by the use of gamma counting techniques. The homogenate (0.1 mm) of a sample of metastatic and non-metastatic tumor was implanted by subcutaneous injection in the right footpad of each animal's hind extremity. The animals bearing metastatic tumor were studied 2-24 days and the non-metastatic group 2-30 days after the implantation of tumor homogenate. The control group consisted of four animals and tumor-bearing groups of seven to eight animals at each time point. All animals were injected with 1.11 MBq of 67Ga citrate by intravenous administration and sacrificed in halothane anesthesia 48 h later. The relative tissue uptake data are presented as arithmetical mean value with a standard error and graphically demonstrated as normalized data with respect to control. The results demonstrate that 67Ga citrate uptake was largely unaffected in most organs by the presence of either metastatic or non-metastatic tumor. Gallium-67 uptake, however, was significantly and consistently increased in the popliteal lymph nodes of the ipsilateral extremity of tumor implant in the metastatic group. No difference was observed in the non-metastatic tumor group. The findings of this experimental work indicate that the host reaction to the tumor does not modify the gallium uptake characteristics in the normal tissues of tumor-bearing animals.