Dysregulation of BMI1 and microRNA-16 collaborate to enhance an anti-apoptotic potential in the side population of refractory mantle cell lymphoma

The proto-oncogene BMI1 and its product, Bmi1, is overexpressed in various types of tumors, particularly in aggressive tumors and tumors resistant to conventional chemotherapy. BMI1/Bmi1 is also crucially involved in cancer-initiating cell maintenance, and is recurrently upregulated in mantle cell lymphoma (MCL), especially aggressive variants. Recently, side population (SP) cells were shown to exhibit tumor-initiating characteristics in various types of tumors. In this study, we show that recurrent MCL cases significantly exhibit upregulation of BMI1/Bmi1. We further demonstrate that clonogenic MCL SP shows such tumor-initiating characteristics as high tumorigenicity and self-renewal capability, and that BMI1 was upregulated in the SP from recurrent MCL cases and MCL cell lines. On screening for upstream regulators of BMI1, we found that expression of microRNA-16 (miR-16) was downregulated in MCL SP cells by regulating Bmi1 in the SPs, leading to reductions in tumor size following lymphoma xenografts. Moreover, to investigate downstream targets of BMI1 in MCL, we performed cross-linking/chromatin immunoprecipitation assay against MCL cell lines and demonstrated that Bmi1 directly regulated pro-apoptotic genes such as BCL2L11/Bim and PMAIP1/Noxa, leading to enhance anti-apoptotic potential of MCL. Finally, we found that a proteasome inhibitor bortezomib, which has been recently used for relapsed MCL, effectively induced apoptosis among MCL cells while reducing expression of Bmi1 and increasing miR-16 in MCL SP. These results suggest that upregulation of BMI1 and downregulation of miR-16 in MCL SP has a key role in the disease's progression by reducing MCL cell apoptosis. Our results provide important new insight into the pathogenesis of MCL and strongly suggest that targeting BMI1/Bmi1 might be an effective approach to treating MCL, particularly refractory and recurrent cases.

Preoperative embolization of meningiomas with N-butyl cyanoacrylate

Meningiomas are often embolized before their surgical resection to reduce blood loss during surgery. Polyvinyl alcohol (PVA) particles have been the most frequently used material for embolization of meningiomas. We have used n-butyl cyanoacrylate (NBCA) as the first-choice material since 2001. Thirty-one meningiomas were embolized with NBCA. We report the result of embolization of meningiomas with NBCA in comparison with PVA particles.

Induced pluripotent stem cells generated from diabetic patients with mitochondrial DNA A3243G mutation

AIMS/HYPOTHESIS

The aim of this study was to generate induced pluripotent stem (iPS) cells from patients with mitochondrial DNA (mtDNA) mutation.

METHODS

Skin biopsies were obtained from two diabetic patients with mtDNA A3243G mutation. The fibroblasts thus obtained were infected with retroviruses encoding OCT4 (also known as POU5F1), SOX2, c-MYC (also known as MYC) and KLF4. The stem cell characteristics were investigated and the mtDNA mutation frequencies evaluated by Invader assay.

RESULTS

From the two diabetic patients we isolated four and ten putative mitochondrial disease-specific iPS (Mt-iPS) clones, respectively. Mt-iPS cells were cytogenetically normal and positive for alkaline phosphatase activity, with the pluripotent stem cell markers being detectable by immunocytochemistry. The cytosine guanine dinucleotide islands in the promoter regions of OCT4 and NANOG were highly unmethylated, indicating epigenetic reprogramming to pluripotency. Mt-iPS clones were able to differentiate into derivatives of all three germ layers in vitro and in vivo. The Mt-iPS cells exhibited a bimodal degree of mutation heteroplasmy. The mutation frequencies decreased to an undetectable level in six of 14 clones, while the others showed several-fold increases in mutation frequencies (51-87%) compared with those in the original fibroblasts (18-24%). During serial cell culture passage and after differentiation, no recurrence of the mutation or no significant changes in the levels of heteroplasmy were seen.

CONCLUSIONS/INTERPRETATION

iPS cells were successfully generated from patients with the mtDNA A3243G mutation. Mutation-rich, stable Mt-iPS cells may be a suitable source of cells for human mitochondrial disease modelling in vitro. Mutation-free iPS cells could provide an unlimited, disease-free supply of cells for autologous transplantation therapy.

Three-dimensional images of liver tumours reconstructed by Gd-EOB-DTPA-enhanced MRI

The purpose of this study was to evaluate three-dimensional images of liver tumours obtained with gadolinium ethoxybenzyl diethylenetriamine penta-acetic acid (Gd-EOB-DTPA)-enhanced MRI (3D-EOB-MRI) in hepatic surgery. We conclude that 3D-EOB-MRI may be an alternative method for depicting liver tumours adjacent to the hepatic veins and portal branches, and may provide additional information for surgical planning.

Evaluation of cervical myelopathy using apparent diffusion coefficient measured by diffusion-weighted imaging

BACKGROUND AND PURPOSE

Intramedullary high signal intensity on T2-weighted imaging was frequently observed in patients with CSM, although this finding does not well correlate with severity or prognosis of CSM. Instead of this nonquantitative information, another measure for CSM is desired. The work was focused primarily on assessing the relationships between ADC values and clinical and radiologic severity for the diagnosis of CSM.

MATERIALS AND METHODS

The relationship between ADC values measured in the spinal cord at 322 intervertebral levels of 66 patients and clinical factors were analyzed.

RESULTS

ADC values in the spinal cord significantly increased with the degree of spinal cord compression and decreased with time after decompression surgery. Patients with higher ADC values had lower preoperative JOA scores and tended to show poorer clinical recovery.

CONCLUSIONS

ADC values appear to indicate the severity of spinal cord compression and clinical recovery after decompression surgery, so spondylotic myelopathy may partly be predicted preoperatively by using ADC values.

Prognosis of high-grade endometrial cancer: a comparison of serous-type and clear cell type to grade 3 endometrioid-type

OBJECTIVE

To evaluate prognosis of high-grade endometrial cancers, comparing serous (SC) and clear cell (CCC) types to grade 3 endometrioid carcinoma (ECG3).

METHODS

Among patients with endometrial cancer treated in two decades, medical records of patients with high-grade endometrial cancer were retrospectively investigated.

RESULTS

Of 447 endometrial cancers, 107 (24%) high-grade endometrial cancers were identified, with the increasing incidence in the last decade (28% vs 19%; p = 0.026). There were 24 SC, 14 CCC and 69 ECG3. Median age was 62, 68, and 61 years, respectively, with the CCC type showing an elder age than the ECG3 type (p = 0.012). The rates of patients with Stage IIIc-IV, lymph node assessment or complete resection at primary surgery, and post-operative chemotherapy were not significantly different; however, response rate to first-line chemotherapy in patients with measurable disease was lower in SC than ECG3 (3 / 11, 27% vs 14 / 19, 74%; p = 0.037), regardless of regimens. Five-year overall survival (OS) was 40%, 71%, and 71% respectively, and five-year progression-free survival (PFS) was 25%, 71%, and 61%, respectively, showing SC with worse prognosis than ECG3 on both OS (p = 0.026) and PFS (p = 0.0028). According to the multivariate analysis, age > or = 70, Stage IIIc-IV and incomplete resection were independent prognostic factors on poor OS, whereas SC, Stage IIIc-IV and incomplete resection were on poor PFS.

CONCLUSIONS

The increasing trend of high-grade endometrial cancer and different outcomes according to histological subtypes, especially poor PFS and chemotherapeutic response in SC, were suggested.

Normal serum CA125 half-life and normal serum nadir CA125 level in patients with ovarian cancers

The normal serum CA125 half-life and distribution of the normal serum nadir CA125 value in patients with epithelial ovarian carcinoma (EOC) have not been determined yet. Among patients with EOC, 41 patients met the inclusion criteria of the present study: the patients that underwent complete cytoreductive surgery and six cycles of platinum-containing chemotherapy, and who had no recurrent disease more than five years. Serum CA125 half-life (T1/2) during primary surgery and primary chemotherapy was calculated and serum nadir CA125 level was evaluated by logarithmic-transformed serum CA125. Median value of nadir CA125 was 7 U/ml (range 3-20 U/ml), and the mean ln (serum nadir CA125) was 1.96 +/- 0.45. Mean T1/2 was 10.4 days in all patients, and T1/2 value was associated with the preoperative serum levels of CA125. Predicted slope of CA125 regression curve was also influenced by the preoperative CA125 value. The present study provides fundamental information with regard to normal half-life time and normal nadir of CA125 in EOC patients.

Correlation between apparent diffusion coefficient and viscoelasticity of articular cartilage in a porcine model

OBJECTIVE

Quantitative MR imaging techniques of degenerative cartilage have been reported as useful indicators of degenerative changes in cartilage extracellular matrix, which consists of proteoglycans, collagen, non-collagenous proteins, and water. Apparent diffusion coefficient (ADC) mapping of cartilage has been shown to correlate mainly with the water content of the cartilage. As the water content of the cartilage in turn correlates with its viscoelasticity, which directly affects the mechanical strength of articular cartilage, ADC can serve as a potentially useful indicator of the mechanical strength of cartilage. The aim of this study was to investigate the correlation between ADC and viscoelasticity as measured by indentation testing.

MATERIALS AND METHODS

Fresh porcine knee joints (n = 20, age 6 months) were obtained from a local abattoir. ADC of porcine knee cartilage was measured using a 3-Tesla MRI. Indentation testing was performed on an electromechanical precision-controlled system, and viscosity coefficient and relaxation time were measured as additional indicators of the viscoelasticity of cartilage. The relationship between ADC and viscosity coefficient as well as that between ADC and relaxation time were assessed.

RESULTS

ADC was correlated with relaxation time and viscosity coefficient (R(2) = 0.75 and 0.69, respectively, p < 0.01). The mean relaxation time values in the weight-bearing and non-weight-bearing regions were 0.61 ± 0.17 ms and 0.14 ± 0.08 ms, respectively.

CONCLUSIONS

This study found a moderate correlation between ADC and viscoelasticity in the superficial articular cartilage. Both molecular diffusion and viscoelasticity were higher in weight bearing than non-weight-bearing articular cartilage areas.

Species differences in tissue distribution and enzyme activities of arylacetamide deacetylase in human, rat, and mouse

Human arylacetamide deacetylase (AADAC) is a major esterase responsible for the hydrolysis of clinical drugs such as flutamide, phenacetin, and rifampicin. Thus, AADAC is considered to be a relevant enzyme in preclinical drug development, but there is little information about species differences with AADAC. This study investigated the species differences in the tissue distribution and enzyme activities of AADAC. In human, AADAC mRNA was highly expressed in liver and the gastrointestinal tract, followed by bladder. In rat and mouse, AADAC mRNA was expressed in liver at the highest level, followed by the gastrointestinal tract and kidney. The expression levels in rat tissues were approximately 7- and 10-fold lower than those in human and mouse tissues, respectively. To compare the catalytic efficiency of AADAC among three species, each recombinant AADAC was constructed, and enzyme activities were evaluated by normalizing with the expression levels of AADAC. Flutamide and phenacetin hydrolase activities were detected by the recombinant AADAC of all species. In flutamide hydrolysis, liver microsomes of all species showed similar catalytic efficiencies, despite the lower AADAC mRNA expression in rat liver. In phenacetin hydrolysis, rat liver microsomes showed approximately 4- to 6.5-fold lower activity than human and mouse liver microsomes. High rifampicin hydrolase activity was detected only by recombinant human AADAC and human liver and jejunum microsomes. Taken together, the results of this study clarified the species differences in the tissue distribution and enzyme activities of AADAC and facilitate our understanding of species differences in drug hydrolysis.

Recovery of the blood flow around the femoral head during early corticosteroid therapy: dynamic magnetic resonance imaging in systemic lupus erythematosus patients

Disturbance of blood supply to the femoral head is a risk factor for corticosteroid-associated osteonecrosis. The aim was to measure blood supply of the proximal femur during corticosteroid therapy in systemic lupus erythematosus (SLE) patients. We repeatedly performed 78 dynamic MRIs of 19 hip joints in 19 SLE patients after initiation of corticosteroid administration for one year. Blood supply of the femoral head (epiphysis, growth plate, and metaphysis), the femoral neck, and the medial circumflex femoral artery were measured in terms of peak percent enhancement. At the first month, blood supply of the growth plate was significantly higher in the pediatric group (<15 years old) than in the adolescent and adult group (>15 years old). At the fourth month, blood supply in every part of the femoral head (epiphysis, growth plate, and metaphysis) was significantly higher in the pediatric group than in the adolescent and adult group. Multiple regression analysis revealed that blood supply to the femoral head depended on the number of days after initiation of corticosteroid administration and the age at the time of dynamic MRI. Blood supply to the femoral head is abundant in pediatric patients and is a function of the number of days after initiation of corticosteroid administration.

Quantitative evaluation and visualization of lumbar foraminal nerve root entrapment by using diffusion tensor imaging: preliminary results

BACKGROUND AND PURPOSE

DTI can provide valuable structural information that may become an innovative tool in evaluating lumbar foraminal nerve root entrapment. The purpose of this study was to visualize the lumbar nerve roots and to measure their FA in healthy volunteers and patients with lumbar foraminal stenosis by using DTI and tractography with 3T MR imaging.

MATERIALS AND METHODS

Eight patients with lumbar foraminal stenosis and 8 healthy volunteers underwent 3T MR imaging. In all subjects, DTI was performed with echo-planar imaging at a b-value of 800 s/mm(2) and the lumbar nerve roots were visualized with tractography. Mean FA values in the lumbar nerve roots were quantified on DTI images.

RESULTS

In all subjects, the lumbar nerve roots were clearly visualized with tractography. In all patients, tractography also showed abnormalities such as tract disruption, nerve narrowing, and indentation in their course through the foramen. Mean FA values were significantly lower in entrapped roots than in intact roots.

CONCLUSIONS

We demonstrated that DTI and tractography of human lumbar nerves can visualize and quantitatively evaluate lumbar nerve entrapment with foraminal stenosis. We believe that DWI is a potential tool for the diagnosis of lumbar nerve entrapment.

Experience with 24 cases of reconstructive anterior skull base surgery: classification and evaluation of postoperative facial appearance

This article details our experience with 24 cases of anterior skull base reconstruction after tumor resection. They were classified into four types according to the resected region. In 11 cases of type I resection, the orbital part of frontal bone and/or cribriform plate of ethmoid bone were resected. In two cases of type II resection, the orbital contents and partial orbital bone were resected with the addition of type I. In five cases of type III resection, the maxillary bone was resected with the addition of type II. In six cases of type IV resection, the zygomatic bone and/or facial skin were resected with the addition of type III. The tumor originating from intracranial region was 25% of this series and all of them belonged to type I. The tumor originating from extracranial region tumor was 75% and its resected region was more extensive. In type I and II resections, the cranial flap, radial forearm free flap, or a combination of the two was used for reconstruction. The rectus abdominis myocutaneous/muscle free flap was used for reconstruction of massive defects in type III and IV defects. Total incidence of postoperative complications was 16.7%. Donor site deformity of the cranial flap at the frontal and temporal region in types I and II resections and facial contour deformity in zygomatic region and defect of upper and/or lower palpebra in type IV resection were major problems with postoperative facial appearance. Although use of the rectus abdominis myocutaneous free flap combined with costal cartilages improved the midfacial contour, palpebral reconstruction remained an unsolved problem in reconstructive skull base surgery. The reconstructive goals in skull base surgery are not only to obtain safe and reliable skull base reconstruction but also to restore the facial appearance postoperatively.

Transforming growth factor-β decreases the cancer-initiating cell population within diffuse-type gastric carcinoma cells

Stem cells in normal tissues and cancer-initiating cells (CICs) are known to be enriched in side population (SP) cells. However, the factors responsible for the regulation of expression of ABCG2, involved in efflux of dyes, in SP cells have not been fully investigated. Here, we characterized the SP cells within diffuse-type gastric carcinoma, and examined the effects of transforming growth factor-β (TGF-β) on SP cells. Diffuse-type gastric carcinoma cells established from four independent patients universally contained SP cells between 1 and 4% of total cells, which displayed greater tumorigenicity than non-SP cells did. TGF-β repressed the transcription of ABCG2 through direct binding of Smad2/3 to its promoter/enhancer, and the number of SP cells and the tumor-forming ability of cancer cells were decreased by TGF-β, although ABCG2 is not directly involved in the tumor-forming ability of SP cells. Cancer cells from metastatic site expressed much higher levels of ABCG2 and included a greater percentage of SP cells than parental cancer cells did. SP cells are thus responsible for the progression of diffuse-type gastric carcinoma, and TGF-β negatively contributes to maintain the CICs within the cancer.

Tetraparesis resembling acute transverse myelitis in a captive chimpanzee (Pan troglodytes): long-term care and recovery

BACKGROUND

A 24-year-old, male chimpanzee (Pan troglodytes) developed acute tetraparesis. Magnetic resonance imaging showed a diffuse T2-weighted hyperintensive lesion, indicating inflammation at the C1-2 level. All infective, autoimmune, and vascular investigations were unremarkable.

RESULTS AND CONCLUSIONS

The chimpanzee's condition most resembled acute transverse myelitis (ATM) in humans. The chimpanzee was in severe incapacitated neurological condition with bedridden status and required 24-hour attention for 2 months followed by special care for over a year. Initially, corticosteroid therapy was performed, and his neurological symptoms improved to some extent; however, the general condition of the chimpanzee deteriorated in the first 6 months after onset. Pressure ulcers had developed at various areas on the animal's body, as the bedridden status was protracted. Supportive therapy was continued, and the general condition, appetite, mobility, and pressure ulcers have slowly but synergistically recovered over the course of 2 years.

Mycobacterial hypersensitivity pneumonitis requires TLR9-MyD88 in lung CD11b+ CD11c+ cells

Mycobacteria are among the most common causes of hypersensitivity pneumonitis (HP), but controversy persists with regard to the involvement of the infectious potency of the organism in mycobacterial HP (hot tub lung). This study aimed to establish a mouse model of hot tub lung to clarify its pathophysiology. Mice were exposed intranasally to formalin-killed Mycobacterium avium from a patient with hot tub lung (HP strain) or chronic pulmonary infection (non-HP strain), and bronchoalveolar lavage fluids and lung tissues were evaluated for allergic inflammation. Dead M. avium HP strain, but not non-HP strain, elicited marked HP-like pulmonary inflammation in wild-type mice. Although the inflammation was induced in mice lacking CD4 or CD8, the induction of HP-like responses was prevented in mice lacking myeloid differentiation factor (MyD)88 or Toll-like receptor (TLR)9. Cultured lung CD11c+ cells responded to M. avium in a TLR9-dependent manner, and reconstitution of TLR9-/- mice with lung CD11c+ cells from wild-type mice restored the inflammatory responses. Further investigation revealed that pulmonary exposure to M. avium HP strain increased the number of lung CD11b+ CD11c+ cells (dendritic cells) through TLR9 signalling. Our results provide evidence that hot tub lung develops via the mycobacterial engagement of TLR9-MyD88 signalling in lung CD11b+ dendritic cells independent of the mycobacterial infectious capacity.

Pocket epithelium in the pathological setting for HMGB1 release

High-mobility group box-1 (HMGB1) protein acts as a transcription factor in the nucleus and also as a pro-inflammatory cytokine when released into extracellular fluids. The presence of higher levels of HMGB1 is reported in the gingival crevicular fluid from periodontal patients. Since the proliferation of bacteria within the periodontal pocket is closely involved in the exacerbation of periodontal disease, it is hypothesized that the periodontal pocket causes the release of HMGB1. Immunohistochemical staining of inflamed gingiva revealed that HMGB1 is exclusively dislocated from the nucleus to the cytoplasm in the pocket epithelium, whereas it is mainly present in the nucleus in the gingival epithelium. Butyric acid, an extracellular metabolite from periodontopathic bacteria populating the periodontal pocket, induced the passive release of HMGB1 as a result of eliciting necrosis in the human gingival epithelial cell line. Thus, the periodontal epithelium may provide a unique pathological setting for HMGB1 release by bacterial insult.

Transforming growth factor-β decreases the cancer-initiating cell population within diffuse-type gastric carcinoma cells

Stem cells in normal tissues and cancer-initiating cells (CICs) are known to be enriched in side population (SP) cells. However, the factors responsible for the regulation of expression of ABCG2, involved in efflux of dyes, in SP cells have not been fully investigated. Here, we characterized the SP cells within diffuse-type gastric carcinoma, and examined the effects of transforming growth factor-β (TGF-β) on SP cells. Diffuse-type gastric carcinoma cells established from four independent patients universally contained SP cells between 1 and 4% of total cells, which displayed greater tumorigenicity than non-SP cells did. TGF-β repressed the transcription of ABCG2 through direct binding of Smad2/3 to its promoter/enhancer, and the number of SP cells and the tumor-forming ability of cancer cells were decreased by TGF-β, although ABCG2 is not directly involved in the tumor-forming ability of SP cells. Cancer cells from metastatic site expressed much higher levels of ABCG2 and included a greater percentage of SP cells than parental cancer cells did. SP cells are thus responsible for the progression of diffuse-type gastric carcinoma, and TGF-β negatively contributes to maintain the CICs within the cancer.

Translation of mRNAs for subunits of chloroplast coupling factor 1 in spinach

The chloroplast coupling factor 1 consists of five nonidentical subunits, three of which (alpha, beta, and epsilon subunits) have been shown in several laboratories to be synthesized within chloroplasts. The site of synthesis of the remaining two (gamma and delta subunits) was investigated by analyzing products directed by spinach leaf RNAs in wheat germ and reticulocyte translation systems in vitro. It was found that poly(A)(+) RNA directs the synthesis of two distinct polypeptides, one of which is immunochemically related to the gamma subunit but is 4,000 daltons larger. The other shares antigenic sites with the delta subunit but is 8,000 daltons larger. When wheat germ or reticulocyte translation systems were programmed with RNAs from purified chloroplasts, the only products related to CF(1) that we could detect were a putative precursor of beta, 2,000 daltons larger than the mature subunit, and some smaller polypeptides, which appear to be incomplete translation products of beta. From these results it appears likely that the gamma and delta subunits are synthesized in the cytoplasm as larger precursors and that beta is synthesized within the chloroplast as a precursor.

Arylacetamide deacetylase is a determinant enzyme for the difference in hydrolase activities of phenacetin and acetaminophen

Phenacetin was withdrawn from the market because it caused renal failure in some patients. Many reports indicated that the nephrotoxicity of phenacetin is associated with the hydrolyzed metabolite, p-phenetidine. Acetaminophen (APAP), the major metabolite of phenacetin, is also hydrolyzed to p-aminophenol, which is a nephrotoxicant. However, APAP is safely prescribed if used in normal therapeutic doses. This background prompted us to investigate the difference between phenacetin and APAP hydrolase activities in human liver. In this study, we found that phenacetin is efficiently hydrolyzed in human liver microsomes (HLM) [CL(int) 1.08 +/- 0.02 microl/(min . mg)], whereas APAP is hardly hydrolyzed [0.02 +/- 0.00 microl/(min . mg)]. To identify the esterase involved in their hydrolysis, the activities were measured using recombinant human carboxylesterase (CES) 1A1, CES2, and arylacetamide deacetylase (AADAC). Among these, AADAC showed a K(m) value (1.82 +/- 0.02 mM) similar to that of HLM (3.30 +/- 0.16 mM) and the highest activity [V(max) 6.03 +/- 0.14 nmol/(min . mg)]. In contrast, APAP was poorly hydrolyzed by the three esterases. The large contribution of AADAC to phenacetin hydrolysis was demonstrated by the prediction with a relative activity factor. In addition, the phenacetin hydrolase activity by AADAC was activated by flutamide (5-fold) as well as that in HLM (4-fold), and the activity in HLM was potently inhibited by eserine, a strong inhibitor of AADAC. In conclusion, we found that AADAC is the principal enzyme responsible for the phenacetin hydrolysis, and the difference of hydrolase activity between phenacetin and APAP is largely due to the substrate specificity of AADAC.