6-(Methylsulfonyl) hexyl isothiocyanate as potential chemopreventive agent: molecular and cellular profile in leukaemia cell lines

Despite numerous therapeutic interventions cancer is still today the second leading cause of death. A growing interest has been addressed to isothiocytanates and more recently, the 6- (methylsulfonyl) hexyl isothiocyanate (6-MITC), the main constituent of the rhizome of Wasabia Japonica, has stimulated the interest of researchers. Aim of the research was to study if 6-MITC is able to modulate the main mechanisms underlying chemopreventive process in leukemic cells lines, verify the selectivity of action and the safety of use in terms of mutagenicity. The study was conducted on different cell types. In particular, Jurkat and HL-60 cells were treated with increasing concentrations of 6-MITC and cell viability, induction of apoptosis, cell cycle analysis, autophagy modulation and stimulation of differentiation were evaluated by flow cytometry. PBL, the non-transformed counterparty of leukemia cells, was used to analyse the selectivity of action by studying the same mechanisms previously indicated. Finally, safety of use and antimutagenicity were studied in TK6 cells adopting an automated protocol in flow cytometry. The achieved results have demonstrated that isothiocyanate modulates many signaling pathways involved in chemopreventive mechanism. In fact, 6-MITC induces apoptosis of both transformed cells, limits tumor growth by slowing down the cell cycle of Jurkat cells and blocks HL-60 cell cycle, increases the autophagic flux and induces cytodifferentiation of promyelocytic HL-60 into macrophage and granulocytic phenotypes. Furthermore, the results obtained with 6-MITC on PBL from healthy donors suggest that the isothiocyante is a good selective cytotoxic agent. Essential feature of a good chemopreventive agent is selectivity toward cancer cells and low toxicity towards non-transformed cells. Finally, the analysis of the micronuclei revealed that 6-MITC is not mutagenic, ensuring safe use, and that instead, it is able to counteract the mutagenic activity of the aneuploidogen Vinblastine, demonstrating another important and interesting chemopreventive activity.

Participant association and emergent curriculum in a MOOC: can the community be the curriculum?

We investigated how participants associated with each other and developed community in a Massive Open Online Course (MOOC) about Rhizomatic Learning (Rhizo14). We compared learner experiences in two social networking sites (SNSs), Facebook and Twitter. Our combination of thematic analysis of qualitative survey data with analysis of participant observation, activity data, archives and visualisation of SNS data enabled us to reach a deeper understanding of participant perspectives and explore SNS use. Community was present in the course title and understood differently by participants. In the absence of explanation or discussion about community early in the MOOC, a controversy between participants about course expectations emerged that created oppositional discourse. Fall off in activity in MOOCs is common and was evident in Rhizo14. As the course progressed, fewer participants were active in Facebook and some participants reported feelings of exclusion. Despite this, activity in Facebook increased overall. The top 10 most active participants were responsible for 47% of total activity. In the Rhizo14 MOOC, both community and curriculum were expected to emerge within the course. We suggest that there are tensions and even contradictions between ‘Community Is the Curriculum’ and Deleuze and Guattari's principles of the rhizome, mainly focussed on an absence of heterogeneity. These tensions may be exacerbated by SNSs that use algorithmic streams. We propose the use of networking approaches that enable negotiation and exchange to encourage heterogeneity rather than emergent definition of community.