Shu Takakura

Oncogenic role of miR-17-92 cluster in anaplastic thyroid cancer cells

Micro RNAs (miRNAs) are non‐coding small RNAs and constitute a novel class of negative gene regulators that are found in both plants and animals. Several miRNAs play crucial roles in cancer cell growth. To identify miRNAs specifically deregulated in anaplastic thyroid cancer (ATC) cells, we performed a comprehensive analysis of miRNA expressions in ARO cells and primary thyrocytes using miRNA microarrays. MiRNAs in a miR‐17‐92 cluster were overexpressed in ARO cells. We confirmed the overexpression of those miRNAs by Northern blot analysis in ARO and FRO cells. In 3 of 6 clinical ATC samples, miR‐17‐3p and miR‐17‐5p were robustly overexpressed in cancer lesions compared to adjacent normal tissue. To investigate the functional role of these miRNAs in ATC cells, ARO and FRO cells were transfected with miRNA inhibitors, antisense oligonucleotides containing locked nucleic acids. Suppression of miR‐17‐3p caused complete growth arrest, presumably due to caspase activation resulting in apoptosis. MiR‐17‐5p or miR‐19a inhibitor also induced strong growth reduction, but only miR‐17‐5p inhibitor led to cellular senescence. On the other hand, miR‐18a inhibitor only moderately attenuated the cell growth. Thus, we have clarified functional differences among the members of the cluster in ATC cells. In conclusion, these findings suggest that the miR‐17‐92 cluster plays an important role in certain types of ATCs and could be a novel target for ATC treatment. (Cancer Sci 2008; 99: 1147–1154)

MiR-195, miR-455-3p and miR-10a* are implicated in acquired temozolomide resistance in glioblastoma multiforme cells

To identify microRNAs (miRNAs) specifically involved in the acquisition of temozolomide (TMZ) resistance in glioblastoma multiforme (GBM), we first established a resistant variant, U251R cells from TMZ-sensitive GBM cell line, U251MG. We then performed a comprehensive analysis of miRNA expressions in U251R and parental cells using miRNA microarrays. miR-195, miR-455-3p and miR-10a( *) were the three most up-regulated miRNAs in the resistant cells. To investigate the functional role of these miRNAs in TMZ resistance, U251R cells were transfected with miRNA inhibitors consisting of DNA/LNA hybrid oligonucleotides. Suppression of miR-455-3p or miR-10a( *) had no effect on cell growth, but showed modest cell killing effect in the presence of TMZ. On the other hand, knockdown of miR-195 alone displayed moderate cell killing effect, and combination with TMZ strongly enhanced the effect. In addition, using in silico analysis combined with cDNA microarray experiment, we present possible mRNA targets of these miRNAs. In conclusion, our findings suggest that those miRNAs may play a role in acquired TMZ resistance and could be a novel target for recurrent GBM treatment.

Dehydroxymethylepoxyquinomicin, a Novel Nuclear Factor-κB Inhibitor, Enhances Antitumor Activity of Taxanes in Anaplastic Thyroid Cancer Cells

Nuclear factor kappaB (NF-kappaB), as an antiapoptotic factor, crucially affects the outcomes of cancer treatments, being one of the major culprits of resistance to chemotherapy. In this study, we investigated whether dehydroxymethylepoxyquinomicin (DHMEQ), a novel NF-kappaB inhibitor, can enhance antitumor activities of taxanes in anaplastic thyroid cancer (ATC) cells. Taxanes induced NF-kappaB activation in ATC cells, which could compromise the therapeutic effect of the drugs. However, DHMEQ, by inhibiting the nuclear translocation of NF-kappaB, completely suppressed the DNA binding capacities of NF-kappaB and lowered the levels of nuclear NF-kappaB protein. Compared with single treatment (either taxane or DHMEQ), the combined treatment strongly potentiated apoptosis, confirmed by cell survival assay; Western blotting for poly (ADP-ribose) polymerase, caspase 3, X-linked inhibitor of apoptosis, and survivin; and flow cytometry for annexin V. Furthermore, we also demonstrate for the first time that the combined treatment showed significantly greater inhibitory effect on tumor growth in a nude mice xenograft model. These findings suggest that taxanes are able to induce NF-kappaB activation in ATC cells, which could attenuate antitumor activities of the drugs, but inhibition of NF-kappaB by DHMEQ creates a chemosensitive environment and greatly enhances apoptosis in taxanes-treated ATC cells in vitro and in vivo. Thus, DHMEQ may emerge as an attractive therapeutic strategy to enhance the response to taxanes in ATCs.

Predictors of menstrual resumption by patients with anorexia nervosa

Objective: To investigate which factors predict the resumption of menstruation by patients with anorexia nervosa (AN). METHODS: Participants were AN patients who, even after weight recovery by inpatient treatment, had prolonged amenorrhea (N=11), AN patients who resumed menstruation after weight recovery (N=9), and age-matched healthy controls (N=12). Anthropometric data and the serum levels of leptin, insulin-like growth factor I (IGF-1), cortisol, luteinizing hormone (LH), estradiol (E2), and other hormones were measured at the beginning of the inpatient treatment and after weight recovery. RESULTS: Of the baseline anthropometric and hormonal factors, logistic regression analysis extracted a high serum cortisol level as a predictor of the inhibition of the resumption of menstruation. After weight recovery, the E2 and leptin levels were significantly higher for eumenorrheic patients than for amenorrheic patients. CONCLUSION: The baseline serum cortisol level was a predictor of the prolonged inhibition of menstrual recovery.

The longitudinal BMI pattern and body composition of patients with anorexia nervosa who require urgent hospitalization: A case control study

BackgroundThe prevention of serious physical complications in anorexia nervosa (AN) patients is important. The purpose of this study is to clarify which physical and social factors are related to the necessity for urgent hospitalization of anorexia nervosa (AN) patients in a long-term starvation state. We hypothesized that the change of longitudinal BMI, body composition and social background would be useful as an index of the necessity for urgent hospitalization.MethodsAN patients were classified into; urgent hospitalization, due to disturbance of consciousness or difficulty walking(n = 17); planned admission (n = 96); and outpatient treatment only groups (n = 136). The longitudinal BMI pattern and the clinical features of these groups were examined. In the hospitalization groups, comparison was done of body composition variation and the social background, including the educational level and advice from family members.ResultsAfter adjusting for age and duration of illness, the BMI of the urgent hospitalization group was lower than that of the other groups at one year before hospitalization (P < 0.01) and decreased more rapidly (P < 0.01). Urgent hospitalization was associated with the fat free mass (FFM) (P < 0.01). Between the groups, no considerable difference in social factors was found.ConclusionsThe longitudinal pattern of BMI and FFM may be useful for understanding the severity in AN from the viewpoint of failure of the homeostasis system.

Regulation of gut luminal serotonin by commensal microbiota in mice

Gut lumen serotonin (5-hydroxytryptamine: 5-HT) contributes to several gastrointestinal functions such as peristaltic reflexes. 5-HT is released from enterochromaffin (EC) cells in response to a number of stimuli, including signals from the gut microbiota. However, the specific mechanism by which the gut microbiota regulates 5-HT levels in the gut lumen has not yet been clarified. Our previous work with gnotobiotic mice showed that free catecholamines can be produced by the deconjugation of conjugated catecholamines; hence, we speculated that deconjugation by bacterial enzymes may be one of the mechanisms whereby gut microbes can produce free 5-HT in the gut lumen. In this study, we tested this hypothesis using germ-free (GF) mice and gnotobiotic mice recolonized with specific pathogen-free (SPF) fecal flora (EX-GF). The 5-HT levels in the lumens of the cecum and colon were significantly lower in the GF mice than in the EX-GF mice. Moreover, these levels were rapidly increased, within only 3 days after exposure to SPF microbiota. The majority of 5-HT was in an unconjugated, free form in the EX-GF mice, whereas approximately 50% of the 5-HT was found in the conjugated form in the GF mice. These results further support the current view that the gut microbiota plays a crucial role in promoting the production of biologically active, free 5-HT. The deconjugation of glucuronide-conjugated 5-HT by bacterial enzymes is likely one of the mechanisms contributing to free 5-HT production in the gut lumen.

The outcome of Japanese anorexia nervosa patients treated with an inpatient therapy in an internal medicine unit

OBJECTIVE: To investigate the outcome of Japanese anorexia nervosa (AN) patients who were treated with the standard Japanese inpatient therapy. METHOD: Of the 88 female AN patients treated with our inpatient therapy between January 1997 and December 2002, 67 (76.1%) who agreed to cooperate in this study were assessed by the Global Clinical Score (GCS) at admission and follow-up, 6.3±1.8 years after discharge. Their clinical characteristics at admission and discharge were also examined. RESULTS: Four (6.0%) patients had died before follow-up. BMI was significantly increased during inpatient therapy. At follow-up, excellent, much improved, symptomatic, and poor outcomes on GCS were 57.1%, 14.3%, 14.3% and 14.3%, respectively. Younger age at admission and larger BMI at discharge were significantly associated with a better outcome. DISCUSSION: This study shows the potential for the use of this method for the treatment of AN patients in countries without specialized eating disorder units.

Psychopathological features of patients with prolonged anorexia nervosa as assessed by the Minnesota Multiphasic Personality Inventory

OBJECTIVE: The duration of illness is quite long in some anorexia nervosa (AN) patients. In the present study, we investigated the psychopathological features of patients with prolonged AN as assessed by the Minnesota Multiphasic Personality Inventory-1 (MMPI-1). METHODS: Fifty-five AN patients completed the MMPI-1 on admission to Kyushu University Hospital from 1999 to 2002. The patients were divided into three groups on the basis of their illness duration: a short-term group, less than 5 years of illness duration (n=31); a middle-term group, from 5 to 10 years (n=14); and a prolonged group, 10 years or more (n=10). RESULTS: The prolonged group scored significantly higher on the MPPI-1 scales of hysteria (Hy), low back pain (Lb) and family conflict than the short-term group. DISCUSSION: AN patients whose illness duration was prolonged characteristically had more hysteria with family conflict. This should be considered in their treatment.

The outcome of treatment for anorexia nervosa inpatients who required urgent hospitalization

BackgroundThis study was done to determine which psychosocial factors are related to the urgent hospitalization of anorexia nervosa patients (AN) due to extremely poor physical condition and to evaluate their outcome after inpatient treatment.Methods133 hospitalized AN patients were classified into an urgent hospitalization (n = 24) or a planned hospitalization (n = 109) group. Multiple regression analysis was done of clinical features, body mass index (BMI), psychological tests [The Minnesota Multiphasic Personality Inventory (MMPI), alexithymia, relationship with parents, and the Eating Disorder Inventory (EDI)]. The effectiveness of treatment was prospectively determined two years after discharge by the Global Clinical Score (GCS). The hospitalized weight gain and the frequency of outpatient visits were evaluated.ResultsOf the factors assessed, only BMI at admission was related to the necessity of urgent hospitalization (β = − 1.063, P = 0.00). The urgent group had significantly more weight loss after discharge and poorer social adaptation on the GCS, even when the patient had a sufficient increase in body weight during inpatient treatment and an equivalent number of outpatient consultations.ConclusionNone of the parameters of the psychosocial tests studied were significantly different between the groups. The outcome of the urgent group was poor. Two years after discharge they had difficulty maintaining weight and continued to have poor social adaptation.

Three cases of appendicitis with anorexia nervosa under inpatient care

BackgroundLittle is known about the occurrence of appendicitis during the re-nourishment period in anorexia nervosa (AN). We report three cases of appendicitis in patients with AN that occurred after hospitalization for treatment of AN.Case presentationCase 1 is a 34-year-old female, case 2 is a 17-year-old female and case 3 is a 38-year-old female. Constipation was observed in all three cases. Careful management of defecation might be essential to prevent appendicitis among AN patients during the re-nourishment period under inpatient care. In addition, mild and diffuse symptoms were observed in all three cases. Therefore, diagnosis proved to be difficult to make and abdominal computed tomography was particularly helpful in all cases. As the symptoms were diffuse, the condition of appendicitis turned out to be more severe and complicated in one case. Additionally, the incidence of appendicitis in AN in the current study might be higher than that in the normal population.ConclusionsThese findings suggest that appendicitis should be considered as one of the potentially important complications in the therapy for AN.