Increased expression of cyclin E is associated with an increased resistance to doxorubicin in rat fibroblasts.

Cell cycle progression in eukaryotic cells is regulated by a family of cyclin-dependent kinases (CDKs). Cyclin E is a regulatory subunit of CDK2 and drives cells from G1 to S phase. Increased expression of cyclin E is a frequent event in human malignancies and has been associated with poor prognosis in various cancers. In this study, we evaluated the effects of cyclin E-overexpression on the sensitivity of rat fibroblasts to anticancer drugs. Cyclin E-overexpressing cells were less sensitive to doxorubicin-induced inhibition of cell growth but not to other antineoplastic drugs, such as paclitaxel, vincristine, etoposide and methotrexate. Cyclin E-overexpressing fibroblasts also displayed a reduction in ROS levels and a significantly lower increase following doxorubicin treatment compared with vector control cells. The expression of manganese superoxide dismutase (MnSOD) and its activity were increased (about 1.3-fold) in cyclin E-overexpressing derivatives compared with control cells. These results suggest that cyclin E overexpression might reduce tumour cells sensitivity to doxorubicin by affecting the expression of MnSOD and that determination of cyclin E expression levels might help to select patients to be treated with an anthracycline-based antineoplastic therapy.

[Benign maxillofacial mucormycosis. Report of a case and review of the literature]. / Mucormicosi maxillo-facciale benigna. Descrizione di un caso e revisione della letteratura.

Mucormycosis is a rare and often lethal infection caused by an opportunistic fungus of the Phycomycetes class. This microorganism is a saprophytic aerobial fungus common in nature and in oral mucosae, nose, paranasal sinus and throat. Mucormycosis has been described in various clinical forms: rhinocerebral, pulmonary, systemic, cerebral and cutaneous, always in immunodepressed patients, with rapid evolution and high rate of mortality. However, rare cases involving maxillofacial area are described in healthy patients with benign evolution and good prognosis as in a case observed at the Department of Maxillofacial Surgery of the University of Naples "Federico II".