Prothymosin alpha expression occurs during G1 in proliferating B or T lymphocytes.
ABSTRACT To gain insight into possible functions for prothymosin alpha in the proliferative cycle of lymphocytes, we examined the kinetics of prothymosin alpha mRNA expression in mitogen stimulated murine lymphocytes. This mRNA increases after mitogen stimulation, peaking in mid G1. This kinetics is compatible with induction of the prothymosin alpha gene by the c-myc protein (Eilers, M., Schirm, S. and Bishop, J.M. (1991) EMBO J., 10, 133-141). Thus, although prothymosin alpha mRNA is found throughout the cell cycle, the elevated expression in G1 may be associated with an increased requirement for prothymosin alpha during the G1/S transition or the S phase of the cell cycle.
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ABSTRACT: Objective: Prothymosin-α, the precursor of thymosin-α1, may play a role in cell proliferation, and the plasma level of thymosin-α1 may reflect the degree of proliferation of the tumor cells. Methods: Recently, a new sandwich immunoradiometric assay for thymosin-α1 was developed using monoclonal and polyclonal antibodies. In this investigation, we used this assay to measure plasma and tissue level of thymosin-α1 in 131 lung cancer patients. Results: We found that the mean plasma thymosin-α1 levels in lung cancer patients were higher than in normal individuals (P<0.001). However, half of the patients showed normal levels. Thymosin-α1 levels correlated neither with the stage nor pathological subtype of the lung cancer, and did not decrease significantly in the 4 weeks after the resection of the tumor. Thymosin-α1 levels of lung cancer patients with another cancer were higher than those without evidence of other cancers (P=0.03). Survival of patients with normal levels of plasma thymosin-α1 was significantly better than that with higher levels (P=0.04). Conclusions: The plasma level of thymosin-α1 may be used as a marker for the prognosis of lung cancer patients. Further investigations are warranted to determine its role in the lung cancer.European Journal of Cardio-Thoracic Surgery 01/1997; · 2.67 Impact Factor
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ABSTRACT: The thymus is a central lymphoid organ with crucial role in generating T cells and maintaining homeostasis of the immune system. More than 30 peptides, initially referred to as "thymic hormones," are produced by this gland. Although the majority of them have not been proven to be thymus-specific, thymic peptides comprise an effective group of regulators, mediating important immune functions. Thymosin fraction five (TFV) was the first thymic extract shown to stimulate lymphocyte proliferation and differentiation. Subsequent fractionation of TFV led to the isolation and characterization of a series of immunoactive peptides/polypeptides, members of the thymosin family. Extensive research on prothymosin α (proTα) and thymosin α1 (Tα1) showed that they are of clinical significance and potential medical use. They may serve as molecular markers for cancer prognosis and/or as therapeutic agents for treating immunodeficiencies, autoimmune diseases and malignancies. Although the molecular mechanisms underlying their effect are yet not fully elucidated, proTα and Tα1 could be considered as candidates for cancer immunotherapy. In this review, we will focus in principle on the eventual clinical utility of proTα, both as a tumor biomarker and in triggering anticancer immune responses. Considering the experience acquired via the use of Tα1 to treat cancer patients, we will also discuss potential approaches for the future introduction of proTα into the clinical setting.Cancer Immunology and Immunotherapy 02/2012; 61(5):599-614. · 3.64 Impact Factor
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ABSTRACT: A genomic clone encoding prothymosin alpha (gene symbol: PTMA), a nuclear-targeted protein associated with cell proliferation, was isolated and the 5'-regulatory region subcloned and sequenced. Because of previously reported discrepancies between several cDNA clones and a genomic clone for prothymosin alpha, we determined the sequence of the first exon and of a 1.7-kb region 5' to the first exon. The sequence of the genomic clone reported here corresponds to the published cDNA sequences, suggesting that the previously noted discrepancies may be due to genetic polymorphism in this region. In addition, our sequence data extend the known 5'-upstream sequence by an additional 1.5 kb allowing the identification of numerous, potential cis-acting regulatory sites. This 5'-flanking cloned probe permitted us to localize the prothymosin gene to chromosome 2 in humans.Human Genetics 03/1993; 90(6):629-34. · 4.63 Impact Factor