A Novel Marker for Purkinje Cells, Ribosomal Protein MPS1/S27: Expression of MPS1 in Human Cerebellum.

BACKGROUND: The ribosomal protein metallopanstimulin-1 (MPS1/S27) serves critical survival purposes in cell division, in normal and cancerous cells; for this reason, selective pressures of evolution have conserved the DNA sequences encoding MPS1/S27 in Archaea and Eukariotic cells. The expression of MPS1/S27 protein in human adult cerebellum has not been established. MATERIAL AND METHODS: The presence of MPS1/S27, was screened in paraffin-embedded human adult brain specimens processed for tissue inmunohistochemistry. Affinity-purified specific antibodies were directed against the N-terminus of MPS1. RESULTS: The antibodies to MPS1 detected Purkinje cells (PC) and their dendrites. In PC, MPS1 antigen-positive staining was found in: the nucleolus, which was strongly stained; ribosomes attached to the external nuclear membrane; cytoplasm of PC, with strong staining in a punctuate fashion; the soma-attached large dendrite trunks of PC, which were MPS1 antigen-positive; and the granular cell layer, where cellular staining in a few cells that appeared to resemble smaller PC was observed. CONCLUSION: Since MPS1 is involved in cell division, DNA repair, and ribosomal biogenesis, it may be a useful antigen for studying processes such as protein synthesis, oncogenesis, regeneration, aging, and perhaps diseases of the human cerebellum.

Increased serum level of RPMPS-1/S27 protein in patients with various types of cancer is useful for the early detection, prevention and therapy.

BACKGROUND: When a protein has a useful and unique function, the selective pressures of evolution conserve the DNA sequences encoding such proteins; the conservation of these domains may have pragmatic use in better understanding viral and spontaneous carcinogenesis in eukaryotic cells. The unique functions of ribosomal protein (RP) Metallopanstimulin-1 (MPS-1/RPS27), and a few other RPs, in growth regulation and carcinogenesis (chemical, viral, radiation and chemotherapy-induced) could be used for the early detection of cancer using serum, or in follow-up therapy. MATERIALS AND METHODS: The MPS-1 serum test was performed in the serum of patients by radioimmunoassay using specific antibodies directed against the N-terminus (amino acids 2 to 17; synthetic peptide) of MPS-1 according to previously described procedures (Fernandez-Pol, JA, 1994). RESULTS: The data presented here indicate that antibodies to MPS-1 detect a zinc finger protein of Mr 9.8 kDa identified by MS and sequencing as MPS-1 in patients having various types of cancer. MPS-1 increases with aggressivity of cancer, irrespective of the cancer types studied in this work. In healthy individuals of the same age range, the levels of MPS-1 increase slowly and progressively at less than 1% per year as the patients age. CONCLUSION: The MPS-1 test may be useful as an aid in: i) early detection of a wide variety of cancer types; and ii) the prognosis and management of cancer patients by following the changes in the concentrations of MPS-1 in serum. Moreover, the results suggest that the combined use of MPS-1 with physical methods of cancer detection such as positron emission tomography, computer assisted tomography, or magnetic resonance imaging techniques may significantly improve the chances of identifying an active tumor in early stages by serodiagnosis of MPS-1. In patients having other diseases (such as rheumatoid arthritis, which manifests as a proliferative disease) or in healthy individuals having no evidence of disease, the identification of as yet unrecognized active oncogenesis, may be significantly improved by using MPS-1. The data on genome context analysis indicates that the presence of MPS-1 in the blood is an indicator of oncogenesis. Thus, the test may be used to help prolong the life of the patients, if the cancer is detected early.

Conservation of multifunctional ribosomal protein metallopanstimulin-1 (RPS27) through complex evolution demonstrates its key role in growth regulation in Archaea, eukaryotic cells, DNA repair, translation and viral replication.

BACKGROUND: When the functions of a protein serve a useful survival and unique purpose, the selective pressures of evolutionary laws of nature conserve the DNA sequences encoding such proteins. In many instances, the conservation of these sequences has occurred since the inception of life on earth to the present in phylogenetically related species. The unique function(s) of metallopanstimulin (MPS-1/RPS27) ribosomal protein (RP) and a limited number of other RPs, in growth regulation, and viral infection is further documented here. Based on the correlation of information concerning Genome Context Analysis, and new information presented here, the author proposes that neutralization or elimination of ribosomal MPS-1/S27 DNA, mRNA or translated protein in eukaryote cells, initiated in the process of chemical, viral or radiation carcinogenesis can result in control of most carcinogenic processes by selective elimination of transformed cells which display overexpression of RPMPS-1/S27, and/or non-lethal pathogenic mutations of RPMPS-1/S27 gene. Recently, critical interactions were reported between RPMPS-1/S27 and p53 induced by DNA damage such as ionizing radiation, or chemotherapy drugs, that result in the activation of p53 which in turn represses RPMPS-1/S27 actions. Thus, p53, RPS27L, and RPS27/MPS-1) regulate growth and survival. MATERIALS AND METHODS: Antivirals were tested in virus-infected cells using: cell culture, cytotoxicity assays, apoptosis, defined virus strains, cloned cells, and RT-PCR. Purity of antivirals was validated by mass spectroscopy (MS). Disruption of zinc finger peptides (ZFPs), by these agents was determined by NMR. RESULTS: The data presented here indicates that anti-ZFP agents can potentially be used to prevent and control viral infections by disrupting viral ZFP motifs. Different DNA/RNA virus-infected cells exposed to the antivirals resulted in distruption of both RPMPS-1/S27 and essential viral ZFPs. Picolinic acid (PA) and fusaric acid (FU) were tested and have been shown to have both antiviral and preventive antiviral activities which have been consistently shown to be mediated, at least in part, via interacting with RPMPS-1/S27. The same antiviral agents simultaneously disrupt essential viral ZFPs. Both antiviral events on ZFPs render the pathogenic virus inactive. CONCLUSION: It is demonstrated here that PA and FU exhibit antiviral activity towards several DNA and RNA viruses of human and animal importance. Illustrative evidence of the mechanism of action was obtained via MS, NMR, and molecular modeling that PA and, more potently, FU, bind to a particular site of the viral ZFPs. Similarly, it was previously shown by MS, NMR and molecular modeling with RPMPS-1/S27 that PA and FU disrupts the function of this RP protein, preventing viral replication by formation of ternary complexes. This work is consistent with a critical role of RPMPS-1/S27 in the life cycle of various viruses and shows that disruption of viral ZFPs is potentially important to control and prevent deathly viral diseases.

Genomics, Proteomics and Cancer: Specific Ribosomal, Mitochondrial, and Tumor Reactive Proteins Can Be Used as Biomarkers for Early Detection of Breast Cancer in Serum.

We have used genomics and proteomics based technologies to study tissue and serum protein profiles in patients with breast cancer (BC) in comparison to control healthy subjects. One critical objective of this study was to identify and characterize new tissue and serum biomarkers of BC using differential screening of a recombinant cDNA human BC expression library. A second major objective of this study was to evaluate the clinical utility of Metallolpanstimulin (MPS-1/S27 ribosomal) protein as a biomarker for the early detection and monitoring of BC by immunoassay measurements of serum MPS-1 protein levels and to identify MPS-1 protein in sera of BC patients. A third objective was to present data on cloned BC genes denoted protein subgroup-30 (PS-30), consisting of mitochondria, nuclear, and ribosomal proteins which are increased after growth factor stimulation of BC cells in tissue culture. To study in detail MPS-1 protein expression in BC, the MPS-1 concentrations were determined in the blood of 117 females free of any disease, and in 203 female patients diagnosed with primary BC. The results indicate that increased serum MPS-1 levels can be used for the early detection of BC. Normal subjects have low concentrations of MPS-1 protein in sera. Moreover, changes in MPS-1 protein serum levels can be used for the study of BC progression or regression after various types of therapy. In both the low and high value range, MPS-1 is 10-fold more effective than CA-15-3 in modifying the probability of the target condition -breast cancer. The use of HPLC, Western blot, Immuno-Mass Spectrometry, and protein sequencing confirmed the presence of authentic MPS-1 in sera of patients with BC. Negligible levels of MPS-1 protein were detected in sera from normal subjects. We conclude that (1) the increase in serum MPS-1 can be used for the early detection of BC; and (2) MPS-1 proved to be reliable in the follow-up of patients with advanced BC as demonstrated by the close correlation between MPS-1 protein levels and BC progression or regression after various types of therapy. Furthermore, all proteins denoted group -30 (Mr <30,000), consisting of ribosomal, nuclear and mitochondria proteins, were found to be significantly increased in BC tissues in comparison to control tissues, suggesting that these proteins may be useful markers for detection of BC. Finally, several serum reactive proteins such as haptoglobin and C3 complement components provided valuable information on oncogenic activity in BC patients.

Metallopanstimulin / S27 Ribosomal Antigen Expression in Stages I and II Breast Cancer: its Relationship with Clinicopathologic Factors.

Metallopanstimulin (MPS-1)/S27 ribosomal protein is involved in cellular proliferation and oncogenesis. In this study, we have examined the expression of the MPS-1 protein in 120 stages I and II breast carcinomas to study its relationship with breast cancer prognosis. We also determined if there was any relationship of MPS-1 with other biological markers commonly used in breast cancer prognosis. The expression of MPS-1 protein was analyzed by immunohistochemistry using specific anti-MPS-1 antibodies. We found that there was greater expression of MPS-1 in tumors of greater size and in higher histological grades. Thus, in tumors with more histological aggressiveness there is more MPS-1. Both were frequently associated with a greater proliferative activity. There was also a significant association between the expression of MPS-1 with the expression of receptors for progesterone (p=0.004), estrogens (p=0.03), bcl-2 (p=0.002), and MIB-1 (p=0.03). After univariate logistic regression analysis, we found that overexpression of MPS-1 correlated with Disease Free Survival (DFS) (p=0.039), showing that MPS-1 positivity is associated with a greater incidence of recurrence and/or metastasis. There was no association between overexpression of MPS-1 and poor Overall Survival (OS) (p=0.146). The results presented here indicate a significant correlation between overexpression of MPS-1/S27 ribosomal protein and more aggressive breast cancer growth. These results suggest that the MPS-1 antigen may be a useful marker to understand better the biological behavior of breast cancer.