Can breast cancer Hsp 27 (Heat Shock Protein 27000) expression influence axillary lymph node status?

The expression of heat shock protein 27 (Hsp 27) in breast cancers correlates with stage of disease, the lower the stage the higher the expression, and with the presence or absence of lymph node metastases; lymph node negative patients being more likely to express Hsp 27 (P<0.04).

[Biology of heat shock proteins]. / Biologia de las proteinas del shock térmico.

Hsp (Heat shock proteins) are a family of constitutive proteins of all pro and eukariotic cells that play different physiological roles: they promote the folding (acquisition of tertiary structure) assembly, translocation and secretion of newly synthesized polypeptides and participate in the removal or repairing of denatured proteins acting as molecular chaperons. This family of proteins is composed by numerous members grouped according to their molecular weight. When cells are subjected to different stresses such as hyperthermic shock, radiation, toxins, viral infections, etc., Hsp are overexpressed. In this way, they exert a cytoprotective effect, making the cells resistant to apoptosis. In humans, Hsp are overexpressed in cancer cells from ovary, endometrium, breast, prostate, digestive tract, etc. In some cases, overexpression is correlated with an unfavorable outcome because these proteins could favour metastatic disease. Some authors associate them not only with proliferation but also with differentiation of the neoplastic tissue. Recent studies show their influence in resistance to chemotherapeutic drugs. In autoimmune diseases like rheumatoid arthritis, Hsp can suppress the inflammatory response. Nevertheless, their role in the immune system has not been well established.

[Dendritic cells and their role in pathology]. / Células dendríticas y su papel en patologia.

The aim of this review is to update the knowledge on dendritic cells (CD), as potent antigen-presenting cells (APC) expressing class II major histocompatibility (MHC) antigen. The different types of DC are derived from a common bone marrow precursor. They differentiate and migrate to lymphoid and non-lymphoid tissues under the influence of diverse stimuli. After binding antigen in their periphery they move to the lymph node activating T cells. Depending on the microenvironment, DC express several surface markers and secrete cytokines such as IL-12, Il-1 and TNF alpha. DC play a role in the pathogenesis of autoimmune and viral diseases being relevant in AIDS. These cells also infiltrate human tumors where they could be involved in the induction of anti-tumor immune response. The immunostimulatory properties of DC are currently applied in DC-based therapies of melanoma and lymphoma patients.

Role of Langerhans cells in the infection of the guinea-pig epidermis with foot-and-mouth disease virus.

In guinea-pig infected with foot-and-mouth disease virus (FMDV), Langerhans cells in the foot pads increase in number and show viral antigens 24 hours post-inoculation, preceding appearance of virus in epithelial cells and vesiculation. This observation suggests that Langerhans cells may be engaged in virus transport from the blood to the non vascularized epidermis.

Langerhans' cells in squamous metaplasia of the human uterine cervix.

The number and shape of Langerhans' cells (LC) were studied by determining cytoplasmic formaldehyde-resistant ATPase activity in whole mounts of normal and metaplastic human cervical epithelium. In normal epithelium the number of LC per square millimeter was 52.75 +/- 2.21. A similar number was found in completely differentiated metaplastic squamous epithelium (49.11 +/- 2.42), but their shape was different with less branching processes. When metaplasia was still incomplete, and numerous mucous cells remained, no LC were present. On the basis of these results it is speculated that mucous cells provide a negative chemotactic stimulus which prevents migration of LC into metaplastic epithelium. When the latter is completely squamous it is repopulated by LC in a fashion similar to normal squamous epithelium.