Disruption of the p16/cyclin D1/retinoblastoma protein pathway in the majority of human hepatocellular carcinomas.

p16, cyclin D1 and retinoblastoma protein (pRB) regulate G1 to S transition and are commonly targeted in various cancers. However, few studies have simultaneously examined all components of the p16/cyclin D1/pRB pathway (RB pathway) in hepatocellular carcinoma (HCC). To clarify the role of the disruption of the RB pathway in HCC, we analyzed p16, pRB and cyclin D1 in 47 HCCs. Inactivation of p16 was detected in 30 of 47 HCCs (64%) by Western blot analysis and significantly correlated with hypermethylation of the promoter of this gene. pRB expression was found to be absent in 13 of 47 HCCs (28%) by immunohistochemistry. We found that 38 of 47 HCCs (81%) contained at least one inactivation in either pRB or p16. Furthermore, there was a significant inverse correlation between p16 and pRB inactivation (p = 0.041). Overexpression of cyclin D1 was detected in 5 of 47 HCCs (11%) by immunohistochemistry. The cases with cyclin D1 overexpression exhibited an advanced clinicopathological appearance and also contained inactivation of pRB and/or p16. These findings suggest that inactivation of pRB and/or p16 is a major event in human hepatocarcinogenesis, while cyclin D1 overexpression may confer additional growth advantages to the tumor in addition to pRB and/or p16 inactivation in HCC.     

Novel orally bioavailable EZH1/2 dual inhibitors with greater antitumor efficacy than an EZH2 selective inhibitor

Polycomb repressive complex 2 (PRC2) methylates histone H3 lysine 27 and represses gene expression to regulate cell proliferation and differentiation. Enhancer of zeste homolog 2 (EZH2) or its close homolog EZH1 functions as a catalytic subunit of PRC2, so there are two PRC2 complexes containing either EZH2 or EZH1. Tumorigenic functions of EZH2 and its synthetic lethality with some subunits of SWItch/Sucrose Non‐Fermentable (SWI/SNF) chromatin remodeling complexes have been observed. However, little is known about the function of EZH1 in tumorigenesis. Herein, we developed novel, orally bioavailable EZH1/2 dual inhibitors that strongly and selectively inhibited methyltransferase activity of both EZH2 and EZH1. EZH1/2 dual inhibitors suppressed trimethylation of histone H3 lysine 27 in cells more than EZH2 selective inhibitors. They also showed greater antitumor efficacy than EZH2 selective inhibitor in vitro and in vivo against diffuse large B‐cell lymphoma cells harboring gain‐of‐function mutation in EZH2. A hematological cancer panel assay indicated that EZH1/2 dual inhibitor has efficacy against some lymphomas, multiple myeloma, and leukemia with fusion genes such as MLL‐AF9, MLL‐AF4, and AML1‐ETO. A solid cancer panel assay demonstrated that some cancer cell lines are sensitive to EZH1/2 dual inhibitor in vitro and in vivo. No clear correlation was detected between sensitivity to EZH1/2 dual inhibitor and SWI/SNF mutations, with a few exceptions. Severe toxicity was not seen in rats treated with EZH1/2 dual inhibitor for 14 days at drug levels higher than those used in the antitumor study. Our results indicate the possibility of EZH1/2 dual inhibitors for clinical applications.     

Superior vena cava syndrome caused by supraclavicular lymph node metastasis of renal cell carcinoma

A 65-year-old woman presented with gross hematuria in February 1997. Left renal tumor was revealed and radical nephrectomy was performed. Pathological examination revealed papillary renal cell carcinoma, pT3aN1M1 (ipsilateral adrenal gland). Interferon-α was administered for 1 year. Two years after the nephrectomy, metastasis to the left supraclavicular lymph node appeared. Seven years after the nephrectomy, the metastatic tumor invaded the brachiocephalic vein and extended to the superior vena cava (SVC), compatible with SVC syndrome. Although interferon-α and external-beam radiotherapy was performed, she died in February 2005. Autopsy revealed a left supraclavicular lymph node metastasis invading the thyroid gland, mediastinum, and brachiocephalic vein. The tumor thrombus descended via the SVC into the right atrium. The right lung artery was obstructed by tumor thrombus. There were no visceral metastases and no local recurrence.     

Clinical implications of leptin and its potential humoral regulators in long-term low-calorie diet therapy for obese humans

OBJECTIVE: To address the clinical implications of leptin and to re-examine the relationship between leptin and its potential humoral regulators such as insulin, nonesterified fatty acids (NEFA) and triiodothyronine (T3) in low-calorie diet (LCD) for obese humans. DESIGN: Longitudinal study. SETTING: University and foundation hospitals. SUBJECTS: Ten obese men and 10 premenopausal obese women. INTERVENTIONS: Five men and five women took 800 kcal/day LCD and another five men and five women took 1400 kcal/day balanced deficit diet (BDD) during 4 weeks. RESULTS: Plasma leptin levels in the LCD group decreased more markedly (46.2+/-14.6 to 13.2+/-3.6 ng/ml) than that expected for the decrement in percentage fat (39.0+/-1.7 to 35.9+/-1.7%) and body mass index (BMI; 35.4+/-2.4 to 33.1+/-2.2 kg/m(2)), while that in the BDD group did not decrease significantly (14.9+/-3.5 to 13.4+/-2.8 ng/ml). The ratio of the decrease in leptin levels to that of BMI during the first week was significantly greater than that during the following 3 weeks (39.5+/-2.7 vs 29.3+/-2.1%, P=0.017). The plasma insulin and T3 levels also fell substantially in the first week and continued to decrease during the entire course. Plasma leptin levels measured weekly in each subject were correlated well with insulin (r=0.586, P=0.0003) and T3 (r=0.785, P=0.0004). Multiple regression analyses after adjustment for the time course and BMI revealed that serum levels of T3 were independently correlated with plasma leptin levels (r=0.928, P<0.0001). The plasma NEFA level was markedly elevated during the first 2 weeks and decreased thereafter. CONCLUSIONS: A rapid fall in leptin during the first week of LCD, coordinated by insulin, T3 and NEFA, should be beneficial for responding to decreased energy intake. Inversely, in view of the powerful effect of leptin on energy dissipation, the present findings suggest the potential usefulness of leptin in combination with caloric restriction for the treatment of obesity. SPONSORSHIP: The Ministry of Education, Culture, Sports, Science and Technology of Japan and the Ministry of Health, Labour and Welfare of Japan.     

Effectiveness of Endoscopic Surgery for Comatose Patients with Large Supratentorial Intracerebral Hemorrhages

To evaluate the effectiveness of endoscopic surgery for life-threatening large brain hemorrhage, we reviewed our empirical cases of comatose patients with large supratentorial intracerebral hemorrhage. Among 35 patients with putaminal or subcortical hemorrhage that was evacuated endoscopically, 14 cases (40%) presented both findings of neurological grade IV for severity and hematoma volume exceeding 70 mL in the recent 3 years (endoscope group), whereas 8 cases with the same conditions were treated by conventional craniotomy for the preceding 3-year period (craniotomy group). Between these two groups, mean age was higher and duration of surgery was shorter in the endoscope group, but no significant differences in hematoma size or evacuation rate were recognized. In the 10 cases that presented with signs of cerebral herniation (neurological grade IVb) and required emergent decompression, the preparation time for surgery tended to be shorter in the endoscope group, although the difference was not significant. Additional ventricular drainage was performed in 7 cases and showed a supplemental effect of reducing intracranial pressure (ICP). Consequently, all patients in the endoscope group were rescued without decompressive large craniectomy, even with symptoms of cerebral herniation. In conclusion, endoscopic surgery has the potential to offer an effective therapeutic option for comatose patients with large supratentorial intracerebral hemorrhages, matching conventional craniotomy for emergent treatment in terms of mortality and management of ICP.     

Endotoxin-induced uveitis causes long-term changes in trigeminal subnucleus caudalis neurons

Endotoxin-induced uveitis (EIU) is commonly used in animals to mimic ocular inflammation in humans. Although the peripheral aspects of EIU have been well studied, little is known of the central neural effects of anterior eye inflammation. EIU was induced in male rats by endotoxin or lipopolysaccharide (LPS, 1 mg/kg ip) given 2 or 7 days earlier. Neurons responsive to mechanical stimulation of the ocular surface were recorded under barbiturate anesthesia at the trigeminal subnucleus interpolaris/caudalis (Vi/Vc) transition and subnucleus caudalis/cervical cord (Vc/C1) junction, the main terminal regions for corneal nociceptors. Two days after LPS, Vc/C1 units had reduced responses to histamine, nicotine, and CO₂ gas applied to the ocular surface, whereas unit responses were increased 7 days after LPS. Those units with convergent cutaneous receptive fields at Vc/C1 were enlarged 7 days after LPS. Units at the Vi/Vc transition also had reduced responses to histamine and CO₂ 2 days after LPS but no enhancement was seen at 7 days. Tear volume evoked by CO₂ was reduced 2 days after LPS and returned toward control values by 7 days, whereas CO₂-evoked eye blinks were normal at 2 days and increased 7 days after LPS. These results indicate that a single exposure to endotoxin causes long-term changes in the excitability of second-order neurons responsive to noxious ocular stimulation. The differential effects of EIU on tear volume and eye blink lend further support for the hypothesis that ocular-sensitive neurons at the Vi/Vc transition and Vc/C1 junction regions mediate different aspects of pain during intraocular inflammation.     

No associations found between the genes situated at 6p22.1, HIST1H2BJ, PRSS16, and PGBD1 in Japanese patients diagnosed with schizophrenia

Recent GWAS demonstrated an association between candidate genes located at region 6p22.1 and schizophrenia. This region has been reported to house certain candidate SNPs, which may be associated with schizophrenia at HIST1H2BJ, PRSS16, and PGBD1. These genes may presumably be associated with pathophysiology in schizophrenia, namely epigenetics and psychoneuroimmunology. A three-step study was undertaken to focus on these genes with the following aims: (1) whether these genes may be associated in Japanese patients with schizophrenia by performing a 1st stage case-control study (514 cases and 706 controls) using Japanese tagging SNPs; (2) if the genetic regions of interest for the disease from the 1st stage of analyses were found, re-sequencing was performed to search for new mutations; (3) finally, a replication study was undertaken to confirm positive findings from the 1st stage were reconfirmed using a larger number of subjects (2,583 cases and 2,903 controls) during a 2nd stage multicenter replication study in Japan. Genotyping was performed using TaqMan PCR method for the selected nine tagging SNPs. Although three SNPs situated at the 3' side of PGBD1; rs3800324, rs3800327, and rs2142730, and two-window haplotypes between rs3800327 and rs2142730 showed positive associations with schizophrenia, these associations did not have enough power to sustain significance during the 2nd stage replication study. In addition, re-sequencing for exons 5 and 6 situated at this region did not express any new mutations for schizophrenia. Taken together these results indicate that the genes HIST1H2BJ, PRSS16, and PGBD1 were not associated with Japanese patients with schizophrenia.