Related Experiment Videos
Microtubule network and microtubule-associated proteins in leukemic T lymphocytes
Abstract:
Cytoskeletal changes have been known to occur in cell transformation. Vinca alkaloids which bind to the tubulin dimer and inhibit microtubule (MT) assembly as well as disrupting the MT network and mitotic spindle, have been used as cancer chemotherapeutic agents. It has been proposed that apart from their anti-mitotic activity, these drugs act on the peripheral MT of malignant cells to produce their cytolytic effects. In this paper we demonstrate the presence of an altered cytoplasmic MT network in MOLT-4 and HuT-78 leukemic cells (human T-cell leukemic lines) compared to normal human peripheral blood lymphocytes stimulated with mitogens. In addition, using a selective extraction protocol we have compared microtubule-associated proteins (MAPs) profiles of G1/S synchronized leukemic human T-cells and 20 h mitogen-stimulated human peripheral blood T-cells. We observed a dramatic decrease in the expression of a MAP of apparent molecular weight 52 kDa and pI 5.2 in the leukemic cells synchronized at the G1/S border of the cell cycle. These results suggest that altered MT network morphology and MAP synthesis may be components of the malignant phenotype in the T-lymphocytic leukemias studied here.
Insights
Altered microtubule networks and decreased expression of a specific microtubule-associated protein (MAP) are observed in T-cell leukemia. These changes may contribute to the malignant phenotype in leukemia.
Area of Science:
- Cell Biology
- Cancer Research
- Biochemistry
Background:
- Cytoskeletal alterations are hallmarks of cell transformation.
- Vinca alkaloids, used in cancer chemotherapy, target microtubules (MTs) and inhibit their assembly.
- These drugs may exert cytolytic effects on malignant cells via peripheral MT disruption.
Purpose of the Study:
- To investigate alterations in the cytoplasmic microtubule (MT) network of human T-cell leukemic lines.
- To compare microtubule-associated protein (MAP) profiles in leukemic T-cells versus normal T-cells.
- To identify potential molecular changes associated with the malignant phenotype in T-lymphocytic leukemias.
Main Methods:
- Comparative analysis of cytoplasmic MT network morphology in MOLT-4 and HuT-78 leukemic cells versus normal lymphocytes.
- Selective extraction protocol to isolate and compare MAPs.
- Analysis of MAP profiles in G1/S synchronized leukemic T-cells and mitogen-stimulated normal T-cells.
Main Results:
- Demonstrated an altered cytoplasmic MT network in MOLT-4 and HuT-78 leukemic cells compared to normal lymphocytes.
- Observed a significant decrease in the expression of a 52 kDa, pI 5.2 MAP in leukemic cells at the G1/S cell cycle border.
- Identified differences in MAP profiles between leukemic and normal T-cells.
Conclusions:
- Altered microtubule network morphology is present in T-cell leukemias.
- Reduced expression of a specific MAP (52 kDa, pI 5.2) is associated with T-cell leukemia.
- Changes in MT network and MAP synthesis may be integral to the malignant phenotype of T-lymphocytic leukemias.