bromochloroacetic-acid and Leukemia--Myeloid

A patient with relapsed acute myelomonocytic leukemia (AML, FAB M4) developed skin infiltration by leukemic blasts. On immunochemistry, the blasts showed "bot" positive cytoplasmic staining for cytokeratins AE1/AE3 and CAM 5.2, resembling the pattern seen in Merkel cell carcinoma of skin. However, the blasts were positive for myeloid markers and negative for cytokeratin 19 and chromogranin. Aberrant immunochemical staining can lead to misdiagnosis unless a panel of antibodies of known specificity is used in tumor diagnosis, and the clinical context is taken into account. The possible role of cytokeratin 19 as a more specific marker for epithelia than keratin cocktails is discussed.

Topics: Acute Disease; Adult; Antigens, CD; Biomarkers, Tumor; Female; Humans; Immunoenzyme Techniques; Keratins; Leukemia, Myeloid; Leukemic Infiltration; Skin

The sensitivity and specificity of a reverse transcription PCR method (RT-PCR) to detect cytokeratin K19 (CK19) expression was evaluated with the purpose of assessing its capability to detect the presence of breast cancer tumour cells in peripheral blood progenitor cell collection that had to be reinfused to breast cancer patients submitted to intensive chemotherapy as haematopoietic support.. Two breast cancers as positive samples were used and 34 samples of mononucleated blood cells as negative controls: 18 peripheral blood samples from normal subjects, 14 from different types of leukaemias (M3, M4Eo, M2, etc.) and two from two patients with Hodgkin's lymphoma. The method studied is a nested RT-PCR that amplifies the CK19 expression from the sample RNA extracted following the method of phenol-chloroform.. The right performance of the method is demonstrated by observing the detection of CK19 transcripts in the breast cancer RNA and by obtaining good blank results both with non transcribed RNA and with DNA. Moreover, the method has an excellent sensitivity such as to allow the detection of CK19 transcripts in a 10(-6) dilution of cDNA reverse transcribed from 1 microgram of breast cancer RNA. The CK19 transcripts were also detected in the 64% of RNA obtained from the mononucleated blood cells controls, although the percentage of positivities was lower (47%) in the RNA from peripheral blood samples. Nevertheless it should be remarked that the levels of CK19 expression in the blood mononucleated cells is almost negligible since it used to extinguish at 1:5 cDNA dilution.. The method studied is specific and has a high sensitivity that explains the detection of CK19 illegitimate expression approximately a half in mononucleated blood cells negative controls. However, the levels of CK19 expression in mononucleated blood cells were almost negligible and it used to extinguish at 1:5 cDNA dilution, therefore it could be concluded that the method might be useful to detect breast cancer occult tumours cells in mononucleated blood cell collection, always provided that a lower amount of cDNA is taken, thus decreasing to nil almost the false positive samples and keeping always a good sensitivity.

Topics: Biomarkers, Tumor; Breast Neoplasms; DNA, Complementary; DNA, Neoplasm; Gene Expression Regulation, Neoplastic; Hodgkin Disease; Humans; Keratins; Leukemia, Myeloid; Neoplasm Proteins; Polymerase Chain Reaction; RNA, Messenger; RNA, Neoplasm; Sensitivity and Specificity

The intermediate filament proteins which include vimentin, desmin, and the keratins are one of three major classes of cytoskeletal proteins in eukaryotic cells. In this study we found that most of the vimentin of undifferentiated HL60 and cells induced to differentiate either along the monocytoid pathway by 12-O-tetradecanoylphorbol-13-acetate (TPA) or along the granulocytic pathway by retinoic acid was soluble in a buffer containing 1% Triton X-100/0.6 mol/l KCl in which the intermediate filament proteins usually are not soluble. HL60 vimentin separated on polyacrylamide gel electrophoresis into two proteins of Mr 55,000 and 54,000 that we detected by immunoblotting. The Mr 55,000 species was the major form in undifferentiated HL60 cells and cells induced by retinoic acid. The distribution of both forms of vimentin changed during induction of differentiation by TPA and after 24 h the Mr 54,000 species was predominant. After an additional 24 h exposure to TPA the relative levels of the two forms of vimentin approached equivalence and a high level of vimentin degradation products was seen. These results suggest that TPA may increase vimentin degradation along a pathway that has a Mr 54,000 intermediate. In addition, the high levels of soluble vimentin in HL60 cells suggests that these cells may be a good model for studying components involved in vimentin assembly.

Topics: Antibodies, Monoclonal; Cell Differentiation; Desmin; Electrophoresis, Polyacrylamide Gel; Humans; Immunoblotting; Keratins; Leukemia, Myeloid; Tetradecanoylphorbol Acetate; Time Factors; Tretinoin; Tumor Cells, Cultured; Vimentin

The expression of intermediate filaments (IMF) by K562 leukemic cell line has been studied by the use of polyclonal and monoclonal antibodies. These cells exhibited an extremely rich network of IMF reacting with both anti-vimentin and anti-keratin antibodies. Although these results need to be confirmed by different techniques, such as immunoblotting, they suggest the possibility that leukemic cell lines can express different types of IMF similarly to other cultured cells.

Topics: Actins; Animals; Cell Line; Cytoskeleton; Humans; Immune Sera; Intermediate Filaments; Keratins; Leukemia, Myeloid; Rabbits; Tubulin; Vimentin