Cytochrome P450 1A1 (CYP1A1) catalyzes the metabolic activation of polycyclic aromatic hydrocarbons (PAHs) such as benzo[a]pyrene (B[a]P) and is transcriptionally regulated by the aryl hydrocarbon receptor (AhR)/AhR nuclear translocator (ARNT) complex upon exposure to PAHs. Accordingly, inhibition of CYP1A1 expression reduces production of carcinogens from PAHs. Although transcription of the CYP1A1 gene is known to be repressed by transforming growth factor-β (TGF-β), how TGF-β signaling is involved in the suppression of CYP1A1 gene expression has yet to be clarified. In this study, using mammalian cell lines, along with shRNA-mediated gene silencing, CRISPR/Cas9-based genome editing, and reporter gene and quantitative RT-PCR assays, we found that TGF-β signaling dissociates the B[a]P-mediated AhR/ARNT heteromeric complex. Among the examined Smads, Smad family member 3 (Smad3) strongly interacted with both AhR and ARNT via its MH2 domain. Moreover, hypoxia-inducible factor 1α (HIF-1α), which is stabilized upon TGF-β stimulation, also inhibited AhR/ARNT complex formation in the presence of B[a]P. Thus, TGF-β signaling negatively regulated the transcription of the CYP1A1 gene in at least two different ways. Of note, TGF-β abrogated DNA damage in B[a]P-exposed cells. We therefore conclude that TGF-β may protect cells against carcinogenesis because it inhibits CYP1A1-mediated metabolic activation of PAHs as part of its anti-tumorigenic activities.

ObjectivesLenalidomide, a hazardous drug, has strict distribution controls. However, the risk of contamination with lenalidomide when patients take the drug has not been studied and the risk of drug exposure to people in the patient’s living environment is unknown. Thus, we investigated the amount of lenalidomide that could be dispersed during the period between removal of the capsule and returning the used blister packages, and we considered the conditions under which lenalidomide could be dispersed and countermeasures.MethodsThe amount of lenalidomide contamination was measured on the outside of the unused blister packages returned by the patients, on the surface of the capsule, and on the inside of the package immediately after removal of the capsule. In addition, the amount of contamination was measured on the blister packages used by the patients and on the gloves worn by the pharmacists on receipt of the packages. Lenalidomide was analysed by liquid chromatography–tandem mass spectrometry.ResultsLenalidomide amounts on the outside of the unused blister packages returned by the three patients were <10, <10, and 26.8 ng/pack, those on the capsule surface immediately after removal from the packages were 297, 388, and 297 ng/capsule, and those on the inside of packages immediately after removal of all capsules were 143, 184, and 554 ng/pack, respectively. A median of 15.6 ng/pack lenalidomide was detected on the surface of packages used by the patients (n=18). The lenalidomide remaining in the packages immediately after capsule removal (~200 ng/pack), except for the 15.6 ng/pack detected in the packages used by the patients, may have been dispersed in the patient’s living environment (~90% or more). The maximum amount of lenalidomide on the surface of the packages used by the patients was over 2500 ng/pack.ConclusionsThe amount of lenalidomide contamination per package was found to be at least 100 ng less after collection by the pharmacist than immediately after removal of the capsules. Therefore, it is recommended to clean the surrounding area and wash one’s hands after taking the capsules.

Cigarette smoking is known to impact the promotion of carcinogenesis and tumor metastasis. On the other hand, some components in smoke were found to have health-promoting effects, and cancer suppressor effects of components in tobacco smoke have attracted attention. Although some studies showed the cancer suppressive effect of cigarette smoke extract (CSE) in vitro study, the effect of CSE administration on cancer is controversial. In this study, we investigated the effect of CSE-administration on tumor metastasis in a spontaneous tumor metastasis model using B16-BL6 cells, which is more clinical conditions. C57BL/6NCr mice were subcutaneously inoculated B16-BL6 cells into the footpad of the right rear leg. CSE was intraperitoneally administrated for 28 days from the day of inoculation. At 2 weeks after inoculation, the primary focus was excised. Subsequently, survival days of the mice were recorded to determine the effect of CSE-administration on spontaneous metastasis. The effect of CSE, α, β-unsaturated ketones, and aldehydes on B16-BL6 cell invasiveness were confirmed by matrigel invasion assay. Survival days of mice injected with 100% CSE was significantly shortened than that of control. B16-BL6 cell invasiveness was accelerated by the treatment with 0.1% CSE and 3 μM of crotonaldehyde. Intraperitoneal CSE-administration may progress spontaneous metastasis of B16-BL6 cells via enhancement of B16-BL6 cell invasiveness. As the cause, we found that crotonaldehyde contained in CSE may enhance the invasion ability of cancer cells. To clarify the cancer-suppressing effect of tobacco components, the effect of crotonaldehyde-removed CSE on tumor should be assessed in detail. Keywords: cigarette smoke extract (CSE), metastasis, crotonaldehyde (CA), B16-BL6 mouse melanoma cells, invasion

Several studies have described factors such as augmented renal clearance that lead to low trough levels of vancomycin (VCM) in patients in the intensive care unit (ICU). In contrast, few studies have examined such factors in patients admitted to general wards. Therefore, the purpose of this study was to clarify factors associated with low VCM trough levels in general ward inpatients. We conducted this retrospective study on patients who had been monitored for changes in VCM blood levels at Gunma University Hospital for a 5-year period from January 1, 2014. Children under 18 years of age, pregnant women, and patients receiving renal replacement therapy were excluded; in total, 217 patients were examined. Subjects were divided into two groups: a low-level group comprising 88 patients with an initial trough concentration of less than 10 µg/mL and an optimal group comprising 129 patients with a trough concentration of 10 -20 µg/mL. Of the 177 general ward patients other than ICU, 74 were in the low-level group and 103 were in the optimal group. Multivariate logistic regression analysis revealed that low uid volume, febrile neutropenia (FN), and non-sepsis were mainly independent risk factors for reduced trough levels. We believe that FN is one of the important risk factors for low trough levels, especially in general ward patients rather than ICU.