Palliative splenic irradiation in primary and post PV/ET myelofibrosis: outcomes and toxicity of three radiation schedules

Splenectomy and splenic irradiation (SI) are the sole treatment modalities to control drug resistant splenomegaly in patients with myelofibrosis (MF). SI has been used in poor surgical candidates but optimal total dose and fractionation are unclear. We retrospectively reviewed 14 MF patients with symptomatic splenomegaly. Patients received a median of 10 fractions in two weeks. Fraction size ranged from 0.2–1.4 Gy, and total dose varied from 2–10.8 Gy per RT course. Overall results indicate that 81.8% of radiation courses achieved a significant spleen reduction. Splenic pain relief and gastrointestinal symptoms reduction were obtained in 94% and 91% of courses, respectively. Severe cytopeni…

Seliciclib (S) Prevents Cyclin A1 DNA Damage Induced Upregulation and Reduces Double Strand Break (DSB) Repair Through NHEJ Impairment

R-Roscovitine (Seliciclib) prevents DNA damage-induced cyclin A1 upregulation and hinders non-homologous end-joining (NHEJ) DNA repair.

Abstract Background CDK-inhibitors can diminish transcriptional levels of cell cycle-related cyclins through the inhibition of E2F family members and CDK7 and 9. Cyclin A1, an E2F-independent cyclin, is strongly upregulated under genotoxic conditions and functionally was shown to increase NHEJ activity. Cyclin A1 outcompetes with cyclin A2 for CDK2 binding, possibly redirecting its activity towards DNA repair. To see if we could therapeutically block this switch, we analyzed the effects of the CDK-inhibitor R-Roscovitine on the expression levels of cyclin A1 under genotoxic stress and observed subsequent DNA damage and repair mechanisms. Results We found that R-Roscovitine alone was unable …

Senescence and p130/Rbl2: a new beginning to the end.

Senescence is the process of cellular aging dependent on the normal physiological functions of non-immortalized cells. With increasing data being uncovered in this field, the complex molecular web regulating senescence is gradually being unraveled. Recent studies have suggested two main phases of senescence, the triggering of senescence and the maintenance of senescence. Each has been supported by data implying precise roles for DNA methyltransferases, reactive oxygen species and other factors. We will first summarize the data supporting these claims and then highlight the specific role that we hypothesize that p130/Rbl2 plays in the modulation of the senescence process.