Monoclonal Antibodies to Ki-67 Protein Suitable for Immunohistochemical Analysis

Monomethine cyanine probes for visualization of cellular RNA by fluorescence microscopy

We have studied spectral-luminescent properties of the monomethine cyanine dyes both in their free states and in the presence of either double-stranded deoxyribonucleic acids (dsDNAs) or single-stranded ribonucleic acids (RNAs). The dyes possess low fluorescence intensity in an unbound state, which is increased up to 479 times in the presence of the nucleic acids. In the presence of RNAs, the fluorescence intensity increase was stronger than that observed in the presence of dsDNA. Next, we have performed staining of live and fixed cells by all prepared dyes. The dyes proved to be cell and nuclear membrane permeant. They are photostable and brightly stain RNA-containing organelles in both live and fixed cells. The colocalization confirmed the specific nucleoli staining with anti-Ki-67 antibodies. The RNA digestion experiment has confirmed the selectivity of the dyes toward intracellular RNA. Based on the obtained results, we can conclude that the investigated monomethine cyanine dyes are useful fluorescent probes for the visualization of intracellular RNA and RNA-containing organelles such as nucleoli by using fluorescence microscopy.

Overexpression of her-2/neu in malignant mammary tumors; translation of clinicopathological features from dog to human

BACKGROUND

Canine mammary gland tumors (CMGTs) are the most common tumor found in bitches. Changes in HER-2/neu genes in human breast cancer (HBC) lead to decrease in disease-free survival (DFS) and overall survival rate (OSR). Previous studies have demonstrated that the biological behavior of malignant mammary gland tumors (MMGTs) is similar to that of HBC. The present study aimed at evaluating the relationship between overexpression of HER-2/neu and clinicopathological features in MMGTs to represent a model of prognostic factors for HBC.

MATERIALS AND METHOD

The clinicopathological data of 35 MMGTs were obtained. Immunohistochemical staining with HER-2, Ki-67 and CD34 markers was conducted with sections from paraffin-embedded blocks. According to standard protocols, histological type, grade, margin status, lymphovascular invasion (LVI), HER-2/ neu score, proliferation rate and microvessel density (MVD) of tumors were determined and the association of HER-2/neu overexpression with these parameters was assessed statistically.

RESULTS

The IHC results showed that 12 (34.3%) cases were HER-2/neu positive. Statistical analyses indicated a significant relationship between HER-2 positivity and tumor grade (p=0.043), which also was demonstrated with cancer stage (p=0.035), tumor margin involvement (p=0.016), proliferation index (p=0.001) and MVD (p=0.001); however, there was no statistical relationship between LVI and tumor size. Overexpression of the HER-2/neu gene in MMGTs results in similar biological behavior as that of HBC; as a result, these tumors have can be considered to have important similarities in clinicopathological characteristics.

CONCLUSIONS

MMGTs can be regarded as an HBC animal model. Further studies in this field would result in new treatments that could be beneficial for both dogs and humans.