Nucleostemin expression in leukemia patients

• Main Authors: Hui-Jen Tsai, 蔡慧珍
• Other Authors: Sheng-Fung Lin
• Format: Others
• Language: zh-TW
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/30744796772415179885

碩士 === 高雄醫學大學 === 醫學研究所碩士班 === 93 === Nucleostemin is a novel protein found in the nucleoli of CNS stem cells, embryonic stem cells of rat and three cancer cell lines of human by McKay and Tsai. Down regulation of nucleostemin was found in the early stage of cell differentiation. Overexpression or depletion of nucleostemin reduces cell proliferation in CNS stem cells and transformed cells of rats. Nucleostemin forms a protein complex with p53 and its effect on cell proliferation is mediated by p53. Mutational studies of nucleostemin cause decreased cell proliferation only in p53(+) cell line, but not in p53 null cell line. Nucleostemin was also found in c-kit+/lin- bone marrow cells but not in granulocytes and lineage-committed B lymphocytes from adult rat. Nucleostemin expression was also found in gastric and liver cancers of human by SJ Liu. Among hematologic malignancies, acute myelogenous leukemia is typically a disease of stem/progenitor cell origin. The leukemic cell share many characteristics with normal hematopoietic stem cells including the ability to renewal. We hypothesize that nucleostemin is expressed in cancer cells of malignancies and possesses a role in the proliferation of cancer cells, including hematologic malignancy. To determine the expression of nucleostemin in leukemia patients, we examined bone marrow from leukemia patients, peripheral blood from normal population by real time quantitative reverse transcription-polymerase chain reaction and western blot analysis for the expression of nucleostemin. There were nucleostemin expression in normal population, acute myeloid leukemia, chronic myeloid leukemia and two hematopoietic cell lines, including K562 and Jurkat. The expression of nucleostemin is decreased in leukemia patients compared with normal population. There is no significant difference of nucleostemin expression in both acute myeloid leukemia and chronic myeloid leukemia patients. Western blot shows expression of nucleostemin in each group. Conclusively nucleostemin is expressed in differentiated leukocytes of normal population and stem cell, blasts-enriched BM of leukemia patients in our study. Whether presence of nucleostemin or altered expression of nucleostemin in leukemia patients cause effect in the pathogenesis of leukemia or associate with the clinical course in leukemia patients? Dose nucleostemin play its role in the regulation of leukemic cell proliferation like a gene regulator, not independently? Further investigations are needed to identify these problems.