Colon cancer stemness as a reversible epigenetic state:Implications for anticancer therapies

The recent discovery of cancer cell plasticity,i.e.their ability to reprogram into cancer stem cells(CSCs)either naturally or under chemotherapy and/or radiotherapy,has changed,once again,the way we consider cancer treatment.If cancer stemness is a reversible epigenetic state rather than a genetic identity,opportunities will arise for therapeutic strategies that remodel epigenetic landscapes of CSCs.However,the systematic use of DNA methyltransferase and histone deacetylase inhibitors,alone or in combination,in advanced solid tumors including colorectal cancers,regardless of their molecular subtypes,does not seem to be the best strategy.In this review,we first summarize the knowledge researchers have gathered on the epigenetic signatures of CSCs with the difficulty of isolating rare populations of cells.We raise questions about the relevant use of currently available epigenetic inhibitors(epidrugs)while the expression of numerous cancer stem cell markers are often repressed by epigenetic mechanisms.These markers include the three cluster of differentiation CD133,CD44 and CD166 that have been extensively used for the isolation of colon CSCs.and.Finally,we describe current treatment strategies using epidrugs,and we hypothesize that,using correlation tools comparing associations of relevant CSC markers with chromatin modifier expression,we could identify better candidates for epienzyme targeting.

Transcriptional and epigenetic regulation of immune tolerance:roles of the NF-κB family members

Immune tolerance is a highly regulated state and involves diverse mechanisms.Central to the induction of tolerance is the targeted modulation of T-cell activities(both effector and regulatory),in which transcription factors play a significant role.The nuclear factor kappa-B(NF-κB)family is a family of transcription factors that not only are critically involved in diverse T-cell responses but also are regulated by many mechanisms to maintain tolerance and T-cell homeostasis.NF-κB,as a transcription factor,has been extensively studied in recent decades,and the molecular mechanisms that regulate NF-κB activities have been well documented.However,recent studies have revealed exciting new roles for NF-κB;in addition to its transcriptional activity,NF-κB can also activate diverse epigenetic mechanisms that mediate extensive chromatin remodeling of target genes to regulate T-cell activities.In this review article,we highlight recent discoveries and emerging opportunities in targeting NF-κB family members as well as their associated chromatin modifiers in the induction of immune tolerance and in the clinical treatment of immune diseases.