Summary Imatinib mesylate (IM) induces remission in chronic myelogenous leukemia (CML) patients but does not eliminate leukemia stem cells (LSC), which remain a potential source of relapse. Here we investigated the ability of HDAC inhibitors (HDACi) to target CML stem cells. Treatment with HDACi combined with IM effectively induced apoptosis in quiescent CML progenitors resistant to elimination by IM alone, and eliminated CML stem cells capable of engrafting immunodeficient mice. In vivo administration of HDACi with IM markedly diminished LSC in a transgenic mouse model of CML. The interaction of IM and HDACi inhibited genes regulating hematopoietic stem cell maintenance and survival. HDACi treatment represents an effective strategy to target LSC in CML patients receiving tyrosine kinase inhibitors.

Chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) is a common condition among men of a wide age range, with detrimental effects on quality of life. The etiology, pathogenesis, and optimal treatment of CP/CPPS remain unknown, although progress has been made in these domains in recent years. A wide variety of pharmacologic and nonpharmacologic therapies have been studied in clinical trials, but most have shown limited efficacy in symptom alleviation. CP/CPPS is increasingly viewed as a condition that involves variable degrees of neuropathic pain. Medications such as gabapentin, pregabalin, memantine, and tricyclic antidepressants are often used in other neuropathic pain conditions and, therefore, are considered potential treatments for CP/CPPS. Few studies of these agents in patients with CP/CPPS have been reported, but future clinical trials should help to determine their utility and to characterize the pathogenetic mechanisms of pain in CP/CPPS. Combining treatment trials with biomarker, genomic, and imaging studies, in addition to epidemiologic and symptom-based assessments, will maximize the ability to probe disease etiology and pathogenesis, as well as identify effective treatment.

Chronic fatigue syndrome (CFS) remains an incompletely characterized illness, in part due to controversy regarding its definition, biological basis and diagnosis. Biomarkers are objective measures that may lead to improvements in our understanding of CFS by providing a more coherent and consistent approach to study, diagnosis and treatment of the illness. Such metrics may allow us to distinguish between CFS subtypes – each defined by characteristic biomarkers – currently conflated under the single, heterogeneous condition of CFS. These delineations, in turn, may guide more granular, focused, and targeted treatment strategies based on more precise characterizations of the illness. Here, we review potential CFS biomarkers related to neurological and immunological components of the illness, and discuss how these biomarkers may be used to move the field of CFS forward, emphasizing clinical utility and potential routes of future research.