Reduced tumour cell proliferation and delayed development of high-grade mammary carcinomas in cathepsin B-deficient mice.

Expression levels of the papain-like cysteine protease cathepsin B (Ctsb) have been positively correlated with mammary tumour progression and metastasis; however, its roles in the hallmark processes of malignant growth remain poorly defined. Using Ctsb-deficient mice we investigated tumour cell differentiation, proliferation and apoptosis in the Tg(MMTV-PyMT) mouse mammary cancer model. Absence of Ctsb significantly impaired development of high-grade invasive ductal carcinomas and reduced the metastatic burden in the lungs.

Tumor cell-derived and macrophage-derived cathepsin B promotes progression and lung metastasis of mammary cancer.

Proteolysis in close vicinity of tumor cells is a hallmark of cancer invasion and metastasis. We show here that mouse mammary tumor virus-polyoma middle T antigen (PyMT) transgenic mice deficient for the cysteine protease cathepsin B (CTSB) exhibited a significantly delayed onset and reduced growth rate of mammary cancers compared with wild-type PyMT mice. Lung metastasis volumes were significantly reduced in PyMT;ctsb(+/-), an effect that was not further enhanced in PyMT;ctsb(-/-) mice.

[Assessment of some metabolic parameters of white rats' liver after exposure to repetitive x-ray or microwave pulses].

Effects of repetitive X-ray and microwave pulses on the rat liver functions were investigated. The action of repetitive nanosecond X-ray is characterized by the metabolic dysfunction of the liver. In particular, it results in a considerable reduction in the ALT activity, augmentation of the AST/ALT ratio and decrease of the total protein content.