University of Bologna

About: University of Bologna is a education organization based out in Bologna, Emilia-Romagna, Italy. It is known for research contribution in the topics: Population & Galaxy. The organization has 38387 authors who have published 115176 publications receiving 3460869 citations. The organization is also known as: Università di Bologna & UNIBO.

MiR-221 controls CDKN1C/p57 and CDKN1B/p27 expression in human hepatocellular carcinoma.

Abstract: The identification of target mRNAs is a key step for assessing the role of aberrantly expressed microRNAs in human cancer. MiR-221 is upregulated in human hepatocellular carcinoma (HCC) as well as in other malignancies. One proven target of miR-221 is CDKN1B/p27, whose downregulation affects HCC prognosis. Here, we proved that the cyclin-dependent kinase inhibitor (CDKI) CDKN1C/p57 is also a direct target of miR-221. Indeed, downregulation of both CDKN1B/p27 and CDKN1C/p57 occurs in response to miR-221 transfection into HCC-derived cells and a significant upregulation of both CDKN1B/p27 and CDKN1C/p57 occurs in response to antimiR-221 transfection. A direct interaction of miR-221 with a target site on the 3' UTR of CDKN1C/p57 mRNA was also demonstrated. By controlling these two CDKIs, upregulation of miR-221 can promote growth of HCC cells by increasing the number of cells in S-phase. To assess the relevance of these studies in primary tumors, matched HCC and cirrhosis samples were assayed for miR-221, for CDKN1B/p27 and CDKN1C/p57 expression. MiR-221 was upregulated in 71% of HCCs, whereas CDKN1B/p27 and CDKN1C/p57 proteins were downregulated in 77% of cases. A significant inverse correlation between miR-221 and both CDKN1B/p27 and CDKN1C/p57 was found in HCCs. In conclusion, we suggest that miR-221 has an oncogenic function in hepatocarcinogenesis by targeting CDKN1B/p27 and CDKN1C/p57, hence promoting proliferation by controlling cell-cycle inhibitors. These findings establish a basis toward the development of therapeutic strategies aimed at blocking miR-221 in HCC.

GMASS ultradeep spectroscopy of galaxies at $z$ ~ 2 - II. Superdense passive galaxies: how did they form and evolve?

Abstract: Aims. The aim of this work is to investigate the physical, structur al and evolutionary properties of old, passive galaxies at z> 1.4 and to place new constraints on massive galaxy formation and evolution. Methods. We combine ultradeep optical spectroscopy from the GMASS project (Galaxy Mass Assembly ultradeep Spectroscopic Survey) with GOODS multi-band (optical to mid‐infrared) photometry and HST imaging to study a sample of spectroscopically identified passive galaxies at 1.39 2. No X-ray emission was found neither from individual galaxies nor from a stacking analysis of the sample. Only one galaxy shows a marginal detection at 24� m. These galaxies have morphologies that are predominantly compact and spheroidal. However, their sizes (Re. 1 kpc) are much smaller than those of spheroids in the present‐day Universe. Their stellar mass surface densities are consequently hig her by≈1 dex if compared to spheroids at z≈ 0 with the same mass. Their rest-frame B-band surface brightness scales with the effective radius, but the offset with respect to the surface brightness of the local Korme ndy relation is too large to be explained by simple passive evolution. At z≈ 1, a larger fraction of passive galaxies follows the z≈ 0 size ‐ mass relation. Superdense relics with Re≈ 1 kpc are extremely rare at z≈ 0 with respect to z> 1, and absent if Re 2. The results are compared with theoretical models and the main implications discussed in the framework of massive galaxy formation and evolution.