Biomedical subjects

Giovanni Alfredo Puca

Publications and source records attributed to Giovanni Alfredo Puca.

3 recordsLinked to original sources

PubMed2005

Modulation of RIZ gene expression is associated to estradiol control of MCF-7 breast cancer cell proliferation.

The retinoblastoma protein-interacting zinc-finger (RIZ) gene, a member of the nuclear protein methyltransferase superfamily, is characterized by the presence of the N-terminal PR domain. The RIZ gene encodes for two proteins, RIZ1 and RIZ2. While RIZ1 contains the PR (PRDI-BF1 and RIZ homologous) domain, RIZ2 lacks it. RIZ gene expression is altered in a variety of human cancers and RIZ1 is now considered to be a candidate tumor suppressor. Estradiol treatment of MCF-7 cells produced a selective decrease of RIZ1 transcript and an increase of total RIZ mRNA. Experiments of chromatin immunoprecipitation indicated that RIZ2 protein expression was controlled by estrogen receptor and RIZ1 had a direct repressor function on c-myc gene expression. To investigate the role of RIZ gene products as regulators of the proliferation/differentiation transition, we analyzed the effects of forced suppression of RIZ1 induced in MCF-7 cells by siRNA of the PR domain-containing form. Silencing of RIZ1 expression stimulated cell proliferation, similar to the effect of estradiol on these cells, associated with a transient increase of c-myc expression.

Breast Neoplasms↗

PubMed2004

The Zn-finger domain of RIZ protein promotes MCF-7 cell proliferation.

In order to understand the oncogenic properties of retinoblastoma-interacting zinc-finger (RIZ) gene products, we produced an MCF-7-derived cell line expressing a fusion protein containing the zinc-finger (aa 359-497) domain of RIZ protein (MCF-7/znf). The Zn-finger domain contains three of the eight putative Zn-finger motifs and is located in proximity of the E1A-like domain containing the Rb protein-binding motif. The MCF-7/znf cells showed a higher growth rate than the parental or the control cell lines, both in hormone-deprived conditions or upon estrogen stimulation. Furthermore, they were less sensitive to the growth inhibitory effect of anti-estrogens and showed a higher level of expression of cyclin D1 and A. The expressed Zn-finger domain recombinant product was localized in the nucleus and in the nucleoli and its expression modified the pattern of actin staining in the cytoplasm. In conclusion the presented results indicated that the Zn-finger domain could be endowed with the putative oncogenic activity of RIZ2 gene product.

Breast Neoplasms↗

PubMed2002

Cytokine pattern in postmenopause.

OBJECTIVE: The present study was undertaken to evaluate the pattern of serum cytokine production in postmenopausal women and the relationship with the hormonal status. A group of fertile women served as controls. METHODS: Eighty-two women in apparent good health, non-smokers and without a history of hormone replacement therapy, were enrolled for the study. The women were divided in two groups according to their hormonal status: fertile women (n=34, age 32 +/- 7 years) and postmenopausal women (n=48, age 54 +/- 8 years). Blood samples were withdrawn in the morning, after an overnight fast. RESULTS: Sex hormones (LH, FSH, Estradiol, Progesterone, DHEA, DHEA-S), as well as GH and IGF-1 levels, were significantly higher in the serum of fertile women as compared with their postmenopausal counterparts. Unlike IL-2, IL-4, IL-5, IL-10, IL-12 and IFN-gamma, significant differences were observed in serum IL-6, IL-18, TNFalpha and TNFbeta between groups: both IL-6 and IL-18 were higher in postmenopausal women, while TNFalpha and TNFbeta were significantly lower. There was an inverse relationship between serum DHEA and DHEA-S levels and both IL-6 (r= -0.46, P<0.02) or IL-18 (r= -0.38, P<0.05) serum concentrations. CONCLUSIONS: Compared with fertile counterparts, women in postmenopause present an alteration in serum cytokine profile suggesting a prevalence of Th2 lymphocytes.

Adolescent↗