A pragmatic factorial randomized controlled trial of transdiagnostic internet-delivered cognitive behavioural therapy: Exploring benefits of homework reflection questionnaires and twice-weekly therapist support.

With the growing demand for internet-delivered cognitive behavioural therapy (iCBT), this pragmatic factorial (2 × 2 × 2) randomized controlled trial evaluated strategies for facilitating iCBT engagement and outcomes in routine care. Specifically, the benefits to patients and therapists of using homework reflection questionnaires and offering patients twice-weekly therapist support were examined. Patients (n = 632) accepted into iCBT for depression and/or anxiety were randomly assigned to complete homework reflection questionnaires or not (factor 1), receive once- or twice-weekly support (factor 2), and to receive care from therapists employed in one of two settings (iCBT clinic or a community mental health clinic; factor 3). Outcomes were measured at pre-treatment, and 8, 12, and 24-weeks post-enrollment. Therapist time was tracked and a focus group was conducted to examine therapist experiences. No differences in patient outcomes were found between therapists employed in the two settings; as such, these two groups were combined for further analyses. In terms of engagement, homework reflection questionnaires were associated with fewer website log-ins and days accessing iCBT; twice-weekly support was associated with more patient emails sent to therapists. Despite engagement differences, homework reflection questionnaires and twice-weekly support did not significantly impact primary outcomes; all groups showed large improvements in depression and anxiety that were maintained at 24-week follow-up. Therapists perceived a number of benefits and challenges associated with responding to homework reflection questionnaires and offering twice-weekly support; most notably the strategies did not benefit all patients. Twice-weekly support was associated with increased therapist time and organizational challenges. It is concluded that neither completion of homework questionnaires nor offering twice-weekly support significantly improve iCBT in routine care.

Sustained Early Disruption of Mitochondrial Function Contributes to Arsenic-Induced Prostate Tumorigenesis.

Arsenic is a well-known human carcinogen that affects millions of people worldwide, but the underlying mechanisms of carcinogenesis are unclear. Several epidemiological studies have suggested increased prostate cancer incidence and mortality due to exposure to arsenic. Due to lack of an animal model of arsenic-induced carcinogenesis, we used a prostate epithelial cell culture model to identify a role for mitochondria in arsenic-induced prostate cancer. Mitochondrial morphology and membrane potential was impacted within a few hours of arsenic exposure of non-neoplastic prostate epithelial cells. Chronic arsenic treatment induced mutations in mitochondrial genes and altered mitochondrial functions. Human non-neoplastic prostate epithelial cells continuously cultured for seven months in the presence of 5 µM arsenite showed tumorigenic properties in vitro and induced tumors in SCID mice, which indicated transformation of these cells. Protein and mRNA expression of subunits of mtOXPHOS complex I were decreased in arsenic-transformed cells. Alterations in complex I, a main site for reactive oxygen species (ROS) production as well as increased expression of ROS-producing NOX4 in arsenic-transformed cells suggested a role of oxidative stress in tumorigenic transformation of prostate epithelial cells. Whole genome cGH array analyses of arsenic-transformed prostate cells identified extensive genomic instability. Our study revealed mitochondrial dysfunction induced oxidative stress and decreased expression of p53 in arsenic-transformed cells as an underlying mechanism of the mitochondrial and nuclear genomic instability. These studies suggest that early changes in mitochondrial functions are sustained during prolong arsenic exposure. Overall, our study provides evidence that arsenic disruption of mitochondrial function is an early and key step in tumorigenic transformation of prostate epithelial cells.

Ionizing radiation induces myofibroblast differentiation via lactate dehydrogenase.

Pulmonary fibrosis is a common and dose-limiting side-effect of ionizing radiation used to treat cancers of the thoracic region. Few effective therapies are available for this disease. Pulmonary fibrosis is characterized by an accumulation of myofibroblasts and excess deposition of extracellular matrix proteins. Although prior studies have reported that ionizing radiation induces fibroblast to myofibroblast differentiation and collagen production, the mechanism remains unclear. Transforming growth factor-ß (TGF-ß) is a key profibrotic cytokine that drives myofibroblast differentiation and extracellular matrix production. However, its activation and precise role in radiation-induced fibrosis are poorly understood. Recently, we reported that lactate activates latent TGF-ß through a pH-dependent mechanism. Here, we wanted to test the hypothesis that ionizing radiation leads to excessive lactate production via expression of the enzyme lactate dehydrogenase-A (LDHA) to promote myofibroblast differentiation. We found that LDHA expression is increased in human and animal lung tissue exposed to ionizing radiation. We demonstrate that ionizing radiation induces LDHA, lactate production, and extracellular acidification in primary human lung fibroblasts in a dose-dependent manner. We also demonstrate that genetic and pharmacologic inhibition of LDHA protects against radiation-induced myofibroblast differentiation. Furthermore, LDHA inhibition protects from radiation-induced activation of TGF-ß. We propose a profibrotic feed forward loop, in which radiation induces LDHA expression and lactate production, which can lead to further activation of TGF-ß to drive the fibrotic process. These studies support the concept of LDHA as an important therapeutic target in radiation-induced pulmonary fibrosis.