Switching from Intravenous to Oral Tacrolimus Reduces its Blood Concentration in Paediatric Cancer Patients.

BACKGROUND/AIM: Tacrolimus is an essential immunosuppressant for successful allogeneic haematopoietic stem cell transplantation (Allo-HSCT). This study aimed to examine the change in the blood concentration of tacrolimus during switching from intravenous to oral administration in allo-HSCT for paediatric cancer to predict the optimal dosage. PATIENTS AND METHODS: We retrospectively examined the medical records of 63 patients who received allo-HSCT and were administered tacrolimus. To compare bioavailability among different dose ranges, the blood concentration was divided by the dose (C/D). RESULTS: Thirty-nine patients (age range=children 1-15 years, adults 17-67 years) were switched to oral administration of tacrolimus. The C/D after switching was significantly lower in children than in adults (p=0.039). There was a strong positive correlation between age and C/D in children, whereas no correlation was observed in adults. CONCLUSION: In paediatric cancer patients, switching tacrolimus administration route may result in reduced blood concentrations. This tendency is more prominent in younger children.

Outcomes of an international volunteer surgical project for patients with cleft lip and/or cleft palate: A mission in developing Laos.

Cleft lip and/or palate (CL/P) is a common birth defect of complex etiology. CL/P surgery is generally performed in infancy to allow for improvements in esthetics, suckling, and speech disorders as quickly as possible. We have engaged in activities such as free-of-charge surgery for CL/P a total of 12 times from 2001 to 2016 in Lao People's Democratic Republic (Laos). The United Nations has designated Laos as a Least Developed Country; it is one of the poorest countries in Asia. We have carried out our activities for a long time, primarily in CL/P patients who cannot undergo surgery for financial reasons, and we have performed CL/P-related surgeries for 283 patients up to 2016. When we began our activities in 2001, the mean age at first cheiloplasty was 11.6 years, which dropped over time until 2016 when the mean age was 1.8 years. A linear regression analysis showed a significant difference between the age at first lip plasty and the year of first operation (ß = -0.35; P < 0.001). This was likely an effect of continuing to train local medical staff in surgical techniques and donating surgical tools and facilities over a period of 16 years while building a good relationship with local staff. However, the healthcare system in Laos is an obstacle to some patients who still cannot undergo CL/P surgery in infancy for financial reasons. We therefore need to support Laos to provide treatment on their own as we continue to carry out our activities for CL/P patients.

CYP1A1 and CYP1A2 expression levels are differentially regulated in three-dimensional spheroids of liver cancer cells compared to two-dimensional monolayer cultures.

Compared to two-dimensional (2D) monolayer cultures, three-dimensional (3D) tumor cell culture models are thought to be structurally more similar to the in vivo tumor microenvironment. We investigated the regulation of the expression of genes encoding the drug-metabolizing enzymes CYP1A1 and CYP1A2 in 3D spheroids comprised of cells of the human hepatocellular carcinoma cell JHH1, Huh7, and HepG2. Expression of CYP1A1 and CYP1A2 in the spheroids was higher than that in 2D cultured cells. Expression of CYP1A1 and CYP1A2 is regulated by aryl hydrocarbon receptor (AhR) in 2D cultured cells. Knockdown of AhR in spheroids suppressed CYP1A1 expression; however, CYP1A2 expression levels remained unchanged. Moreover, we found that pregnane X receptor (PXR) likely regulated CYP1A2 expression in JHH1, HepG2, and Huh7 spheroids and that CYP1A1 expression in JHH1 and Huh7 3D spheroids is regulated not only by AhR but also by PXR. It is well known that gene expression levels are different between 3D spheroids and 2D monolayer cultured cells, and our results indicate that the regulation of gene expression also varies between the two culture conditions. Taken together, these results underlie a novel finding regarding the regulation of drug-metabolizing enzyme expression in liver cancer cells growing as 3D spheroids.