miR-194-5p/BCLAF1 deregulation in AML tumorigenesis.

This corrects the article DOI: 10.1038/leu.2017.64.

miR-194-5p/BCLAF1 deregulation in AML tumorigenesis.

Deregulation of epigenetic mechanisms, including microRNA, contributes to leukemogenesis and drug resistance by interfering with cancer-specific molecular pathways. Here, we show that the balance between miR-194-5p and its newly discovered target BCL2-associated transcription factor 1 (BCLAF1) regulates differentiation and survival of normal hematopoietic progenitors. In acute myeloid leukemias this balance is perturbed, locking cells into an immature, potentially 'immortal' state. Enhanced expression of miR-194-5p by treatment with the histone deacetylase inhibitor SAHA or by exogenous miR-194-5p expression re-sensitizes cells to differentiation and apoptosis by inducing BCLAF1 to shuttle between nucleus and cytosol. miR-194-5p/BCLAF1 balance was found commonly deregulated in 60 primary acute myeloid leukemia patients and was largely restored by ex vivo SAHA treatment. Our findings link treatment responsiveness to re-instatement of miR-194-5p/BCLAF1 balance.

[State of the art and therapeutic prospects in neuroectodermal tumours and other neuroendocrine pathologies]. / Attualità e prospettive terapeutiche nei tumori neuroectodermici e nelle altre patologie neuroendocrine.

The clinical and biological characteristics of neuroectodermal tumours (NETs) are such that their treatment is necessarily multidisciplinary. Surgery is the first therapeutic choice given that it is the only potentially curative treatment for this type of neoplasm. Medical treatment is mainly indicated in the treatment of metastatic disease and must be separated into three basic options: chemotherapy, immunotheraphy and hormone treatment. Owing to the low proliferative index generally found in NETs, chemotherapy is not very effective as a means of controlling tumour growth. Data in the literature on interferon suggest that it plays a limited role in the treatment of NETs, as do the preliminary results from studies on the association of interferon + chemotherapy. The introduction of somatostatin analogs in clinical practice represents an effective tool in the therapeutic strategy for NETs and has opened new possibilities for the management of other neoplasms. One particularly interesting aspect of the octreotide-mediated antitumour action concerns the blocking of tumour neo-angiogenesis. The majority of non-endocrine tumours also express specific somatostatin receptors and in theory it is possible to hypothesise an antiproliferative action also in tumours without these receptors mediated by the indirect antiproliferative effects of somatostatin.

The antiestrogen ICI 182,780 inhibits proliferation of human breast cancer cells by interfering with multiple, sequential estrogen-regulated processes required for cell cycle completion.

Antiestrogens are widely used for breast cancer treatment, where they act primarily by inhibiting the mitogenic action of estrogens on tumor cells. The effects of the pure antiestrogen ICI 182,780 on estrogen-regulated cell cycle phase-specific events were investigated here in synchronously cycling human breast cancer (HBC) cells. In early G(1)-arrested MCF-7 or ZR-75.1 cells, 17beta-estradiol (E2) induces rapid activation of the cyclin/Cdk/pRb pathway, as demonstrated by D-type G(1) cyclins accumulation during the first few hours of hormonal stimulation, followed by sequential accumulation of E, A and B1 cyclins and progressive pRb phosphorylation, as cells progress through the cell cycle. When added to quiescent cells together with E2, ICI 182,780 prevents all of the above hormonal effects. Interestingly, in mid-G(1) cells (2-8 h into estrogen stimulation) the antiestrogen causes rapid reversal of hormone-induced D-type cyclins accumulation and pRb phosphorylation, and still fully inhibits G(1)-S transition rate, while in late-G(1) cells it does not prevent S phase entry but still inhibits significantly DNA synthesis rate, S-phase cyclins accumulation and pRb hyperphosphorylation. These results indicate that pure antiestrogens prevent multiple estrogen-induced cell cycle-regulatory events, each timed to allow efficient G(1) completion, G(1)-S transition, DNA synthesis and cell cycle completion.