The Yin Yang 1 (YY1) transcription factor has a pivotal role in normal biological processes such as development, differentiation, replication and cell proliferation exerting its effects on a huge number of genes involved in these processes. Mechanisms of YY1 action are related to its ability to initiate, activate, or repress transcription depending upon the context in which it binds. The role of YY1 played in cancer has been recently explored. This article summarizes the most relevant studies focused on YY1 regulation and dwells on the way how its overexpression may affect the clinical behavior of several cancer types. Furthermore, the contribution of the upregulation of YY1 exerted in response to therapeutic-induced apoptosis is discussed.

To investigate the tumor fraction with cancer stem/tumor initiating cell (CSC/TIC) characteristics, we tested the human cervical carcinoma cell lines A431, Caski and SiHa, by growth as non-adherent spheres in specific media and aldehyde dehydrogenase (ALDH) enzymatic activity. A good correlation between the two parameters was observed and the highest levels were observed in A431 cell line that was selected for characterization of the CSC/TIC fraction. A431 parental cells already displayed characteristics common to CSC/TIC, such as sphere forming efficiency, adherent holoclone formation and high ALDH activity. Non-adherent spheres maintained or increased these properties, and, in particular, ALDH-positive fraction increased from 46 to 65% and a transient induction of stem cell markers such as Nanog, Nestin and Oct4 was observed. Furthermore, a significant increase of paraclone forming cells was observed, suggesting that differentiation took place inside sphere cell populations. As compared to parental cells, spheres were characterized by: (1) a ten-fold higher verapamil-sensitive side population fraction; (2) the appearance of a podoplanin-positive subpopulation characterized by a small cell size; (3) the ability to propagate tumors in nude mice at a lower cell dose. The global gene expression analysis demonstrated a strong and reversible modulation of 'sphere' phenotype in comparison to parental and sphere cells re-induced to adherent conditions. All together our results indicated that the growth of A431 cells as a non-adherent sphere was not sufficient by itself to define a stem-like population, but it was essential for the emergence of a small population of tumor cells with CSC properties.

Motor cortex stimulation is a minimally invasive surgical procedure used for pain control. The authors report their results treating two patients with typical Parkinson disease. Unilateral motor cortex stimulation proved to be beneficial bilaterally. Motor cortex stimulation may represent a cost-effective alternative to deep brain stimulation.

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