The clinicopathological significance of BUBR1 overexpression in hepatocellular carcinoma

BACKGROUND AND AIMS

BUBR1 is a key component of the mitotic spindle checkpoint, and its roles in human cancers are controversial and unclear. The aim of this study was to investigate the clinicopathological significance of BUBR1 expression in hepatocellular carcinoma (HCC).

METHODS

The BUBR1 protein and its mRNA levels were measured in 58 HCCs, nine high-grade dysplastic nodules and their paired non-tumorous liver tissues by quantitative real-time polymerase chain reaction (qPCR) and western blot, respectively. In addition, immunochemical analysis of the BUBR1 protein was performed in 458 HCCs and 46 dysplastic nodules, and the clinicopathological significance of the BUBR1 expression was evaluated.

RESULTS

The BUBR1 expression at both mRNA and protein levels was elevated in two of nine high-grade dysplastic nodules and in 37 of 58 (64%) HCCs. BUBR1 was overexpressed in 207 of 458 (45%) HCCs by immunohistochemistry. Intriguingly, high expression of the BUBR1 was correlated with larger tumour size, higher histological grade, advanced pathological stage, and poor overall and recurrence-free survival. There was a higher frequency of BUBR1 overexpression in cases with positive serum HBsAg than those with negative HBsAg. Moreover, BUBR1 overexpression was associated with P53 staining and high Ki67 labelling indices in HCC tissues.

CONCLUSIONS

BUBR1 was overexpressed in about 45% HCCs, and its overexpression may be a relative lately event in HCC progression. Overexpression of BUBR1 was associated with worse prognosis and is a potential prognostic factor for patients with HCC.

Marginal hazards model for case-cohort studies with multiple disease outcomes

Case-cohort study designs are widely used to reduce the cost of large cohort studies while achieving the same goals, especially when the disease rate is low. A key advantage of the case-cohort study design is its capacity to use the same subcohort for several diseases or for several subtypes of disease. In order to compare the effect of a risk factor on different types of diseases, times to different events need to be modelled simultaneously. Valid statistical methods that take the correlations among the outcomes from the same subject into account need to be developed. To this end, we consider marginal proportional hazards regression models for case-cohort studies with multiple disease outcomes. We also consider generalized case-cohort designs that do not require sampling all the cases, which is more realistic for multiple disease outcomes. We propose an estimating equation approach for parameter estimation with two different types of weights. Consistency and asymptotic normality of the proposed estimators are established. Large sample approximation works well in small samples in simulation studies. The proposed methods are applied to the Busselton Health Study.

Characterization of a major colon cancer susceptibility locus (Ccs3) on mouse chromosome 3

Treatment of mice with the carcinogen azoxymethane (AOM) induces a number of lesions in the colon, including hyperplastic lesions, as well adenomas and carcinomas in situ. Inbred strains of mice show different responses to AOM-induced carcinogenesis. A/J mice are highly susceptible and develop a greater number of hyperplastic lesions and tumors (15-70 tumors per mouse) than resistant C57BL/6J mice (0-6 tumors per mouse). Susceptibility to AOM-induced tumors segregates as a co-dominant trait in (A x B6)F1 hybrids. Using a set of 23 AcB and BcA recombinant congenic mouse strains derived from A/J (susceptible) and B6 (resistant) parents, we observed that the number of hyperplastic lesions and tumors induced by AOM was under different genetic controls in AcB/BcA strains. The multiplicity of AOM-induced tumors is controlled by a major locus that we have mapped on the distal portion of chromosome 3, to which we have given the temporary designation colon cancer susceptibility locus 3 (Ccs3). B6 and A/J alleles at Ccs3 are associated with resistance and susceptibility, respectively. Haplotype analysis in key informative AcB/BcA strains restricts the size of the Ccs3 locus to a 14 Mb segment that contains 94 annotated genes. The expression level of all these genes in normal colon has been established by transcript profiling with microarrays, and has led to the identification of a subset of positional candidates that are expressed at high levels in this tissue. The 4q and 1p human chromosomal segments sharing syntenic homology with the mouse Ccs3 segment are known to be associated with inflammatory bowel diseases and colorectal tumors in humans, suggesting that the study of the mouse Ccs3 locus may help further the pathogenesis of these human conditions.

Prevention of excess gain

Obesity prevention trials are designed to promote healthy weight. The success of these trials is often assessed using one of three metrics--means, incidence or prevalence. In this study, we point out conceptual shortcomings of these metrics and introduce an alternative that we call 'excess gain'. A mathematical demonstration using simulated data shows a scenario in which the statistical power of excess gain compares favorably with that of incidence and prevalence. Prevention of excess gain communicates an easily understood public health message that is applicable to all individuals regardless of weight status.

Osteopontin induces angiogenesis through activation of PI3K/AKT and ERK1/2 in endothelial cells

Angiogenesis is a key step in tumor growth and metastasis. The mechanism by which osteopontin (OPN) induces the angiogenesis of endothelial cells remains unclear. Here, we show that OPN confers cytoprotection through the activation of the PI3K/Akt pathway with subsequent upregulation of Bcl-xL and activation of nuclear factor-kappaB. OPN enhances the expression of vascular endothelial growth factor (VEGF) through the phosphorylation of AKT and extracellular signal-regulated kinase (ERK). In turn, OPN-induced VEGF activates PI3K/AKT and the ERK1/2 pathway as a positive feedback signal. Blocking the feedback signal by anti-VEGF antibody, PI3-kinase inhibitor or ERK inhibitor can partially inhibit the OPN-induced human umbilical vein endothelial cell (HUVEC) motility, proliferation and tube formation, while blocking the signal by anti-OPN or anti-alphavbeta3 antibody completely abrogates the biological effects of OPN on HUVECs. In addition, blood vessel formation is also investigated in vivo. The antiangiogenesis efficacy of anti-OPN antibody in vivo is more effective than that of anti-VEGF antibody, which only blocks the feedback signals. These data show that OPN enhances angiogenesis directly through PI3K/AKT- and ERK-mediated pathways with VEGF acting as a positive feedback signal. The results suggest that OPN might be a valuable target for developing novel antiangiogenesis therapy for treatment of cancer.

Significance of phosphatase and tensin homologue (PTEN), O(6)-methylguanine-DNA methyltransferase (MGMT), and DNA-dependent protein kinase catalytic subunit (DNA-PKcs) protein expression in gynaecomastia

This study was designed to investigate the pathogenesis of gynaecomastia by measuring phosphatase and tensin homologue (PTEN), O(6)-methylguanine-DNA methyltransferase (MGMT) and DNA-dependent protein kinase catalytic subunit (DNA-PKcs) protein in breast tissue specimens from 68 patients with gynaecomastia and 24 normal male controls using immunohistochemical staining. The gynaecomastia cases were divided into three different histological types: florid, intermediate and fibrous. The PTEN, MGMT and DNA-PKcs proteins were detected in both gynaecomastia and normal breast tissue, but the levels of immunohistochemical staining of each protein were significantly lower in gynaecomastia breast tissue than in normal breast tissue. There were also significant differences in the levels of immunohistochemical staining for the three proteins according to gynaecomastia histological type. These results suggest that abnormally low levels of PTEN, MGMT and DNA-PKcs protein in gynaecomastia breast tissue may play a role in the development of gynaecomastia. Further research is required to elucidate fully their individual roles in the pathophysiology of gynaecomastia.

Expression of LHRH receptors in prostate cancer cells prior to therapy, following castration, or following treatment with LHRH agonists

5163

Background: In the treatment of advanced prostate cancer, the effects of luteinizing hormone releasing hormone (LHRH) agonists are mediated through the down-regulation of pituitary LHRH receptors, inhibiting the pituitary-gonadal axis. Several groups have demonstrated LHRH receptor expression on prostate cancer cells. These tumoral receptors have been shown to mediate direct inhibitory effects in vitro. That expression of LHRH receptors persists in the castrate resistant state. To date, there is no information on LHRH receptor expression on the prostate after LHRH agonist therapy. This study investigates the expression of LHRH receptors following prolonged exposure to LHRH agonists. Methods: Expression of LHRH receptors was determined using immunohistochemistry and the intensity was graded on a scale from zero to 3. The expression was analyzed in three cohorts of patients: (1) 47 men with localized prostate cancer treated with radical prostatectomy with no hormone therapy, (2) 61 men with localized prostate cancer treated with neoadjuvant LHRH agonists for varying duration prior to prostatectomy, and (3) 22 men with metastatic prostate cancer who received a palliative transurethral resection of the prostate after clinical progression. In the final cohort, 15 men were treated with castration and 7 were treated with LHRH agonists. Results: 45 of 47 hormone naïve samples (95.7%) demonstrated LHRH receptor expression. Statistical analysis revealed a correlation between strong receptor expression and higher pathologic tumor stage as well as shorter overall survival. 60 of 61 samples treated with neoadjuvant LHRH agonist therapy (98.4%) demonstrated LHRH receptor expression. All 22 samples from patients with metastatic disease demonstrated LHRH receptor expression. The majority of these samples demonstrated moderate to strong intensity. Conclusions: LHRH receptors are expressed on prostate cancers cells of hormone naïve and castrated patients. The expression of these receptors appears to persist despite prolonged treatment with LHRH agonists. The continued expression of these receptors supports the concept of targeting prostatic LHRH receptors to deliver cytotoxic therapy based on LHRH analogs, such as AN-152.

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Impact of overweight and obesity on hospitalization: race and gender differences

OBJECTIVE

To examine associations between weight status and number of all-cause and cause-specific hospitalizations overall, and by race and gender.

DESIGN

Longitudinal cohort study.

SUBJECTS

White and black adults (n=15 355) from the Atherosclerosis Risk in Communities Study who were normal weight (body mass index: >or=18.5 to <25.0 kg m(-2); n=4997), overweight (>or=25.0 to <30.0 kg m(-2); n=6100), or obese (>or=30.0 kg m(-2); n=4258) at baseline.

MEASUREMENTS

Information on hospitalizations was collected using community and cohort surveillance methods. Negative binomial models adjusted for race, gender, field center, age, physical activity, education level, smoking status, alcoholic beverage consumption and health insurance at baseline. Adjusted numbers of hospitalizations were calculated after setting covariates to the mean value (for continuous variables) or to the average distribution (for categorical variables) observed in the entire cohort and are expressed as the number of hospitalizations per 1000 adults followed over a period of 13 years.

RESULTS

The covariate-adjusted average number of all-cause hospitalizations was 1316 per 1000 normal weight, 1543 per 1000 overweight and 2025 per 1000 obese. Normal weight women had significantly fewer hospitalizations than normal weight men (1173 versus 1515 per 1000), but the increase associated with being obese on the number of all-cause hospitalizations was larger in women than men (791 versus 589 per 1000). There was no significant difference detected between the number of hospitalizations in normal weight whites and blacks, and the increase in hospitalizations with overweight or obesity was also not different. Effects of weight status on several primary causes of hospitalization differed by gender and race group.

CONCLUSION

Our work suggests that obesity prevention may reduce hospitalizations, a major component of rising healthcare costs. The impact of successful obesity prevention is likely to be larger in women than in men, and similar in blacks and whites.

Decorin-mediated inhibition of proliferation and migration of the human trophoblast via different tyrosine kinase receptors

Decorin (DCN), a decidua-derived TGFbeta-binding proteoglycan, negatively regulates proliferation, migration, and invasiveness of human extravillous trophoblast (EVT) cells in a TGFbeta-independent manner. The present study examined underlying mechanisms, in particular possible roles of epidermal growth factor receptor (EGFR), IGF receptor (IGFR)-I, and vascular endothelial growth factor receptor (VEGFR)-2. EVT cell sprouting from first-trimester chorionic villus explants in the presence or absence of TGFbeta-neutralizing antibody was inhibited with DCN, suggesting its negative regulatory role in situ. Inhibition of migration of the human EVT cell line HTR-8/SVneo in transwells undercoated with fibronectin was stronger when cells were briefly preincubated with DCN at 4 C (known to retard dissociation of receptor-ligand complex) than at 37 C, suggesting possible DCN action by cell membrane binding. Pretreatment of cells with an IGFR-I blocking agent, but not two EGFR blocking agents or a VEGFR blocking agent, significantly abrogated migration inhibitory effects of DCN, suggesting the involvement of IGFR-I but not EGFR or VEGFR in migration inhibition by DCN. On the other hand, pretreatment with either of the EGFR blocking agents, or the VEGFR blocking agent but not the IGFR-I blocking agent, blocked proliferation inhibitory effects of DCN, indicating the roles of EGFR and VEGFR, but not IGFR-I in antiproliferative action of DCN. EVT cells expressed EGFR, IGFR-I, and VEGFR-2. IGFR-I and VEGF-R2 were phosphorylated in the presence of their natural ligands as well as DCN, and these events were blocked by pretreatment with respective receptor blocking agents indicating DCN-mediated activation of these receptors. In conclusion, DCN effects on EVT cells are mediated selectively by multiple tyrosine kinase receptors.

Enhanced bactericidal activity against Escherichia coli in calves fed Morinda citrifolia (Noni) puree

BACKGROUND

Although adequate colostrum intake and properly used antibiotics can provide much protection for the bovine neonate, increased antibiotic scrutiny and consumer demand for organic products have prompted investigations of natural immunomodulators for enhancing calf health. One plant-based immunomodulator, Morinda citrifolia (noni) fruit, is a well-recognized natural product that has a broad range of immunomodulatory effects.

HYPOTHESIS

Neonatal calves fed noni puree would demonstrate whole blood phagocytic capacity in Gram-negative and Gram-positive in vitro assays.

ANIMALS

Blood samples from 18 neonatal Holstein bull calves.

METHODS

Calves were divided into 2 groups: Group 1 comprised control calves, whereas Group 2 received 30 mL of noni puree twice a day in milk replacer. Day 0 blood samples were obtained between 36 and 48 hours of age before the first feeding of puree. Ethylenediaminetetraacetic acid anticoagulated blood was collected from each calf on days 0, 3, 7, and 14. Bactericidal assays were performed to estimate the percentage killing of Escherichia coli and Staphylococcus epidermidis.

RESULTS

Blood samples from noni puree-fed calves displayed significantly more E. coli bacterial killing than did controls on day 14, and although differences were not significant on days 0, 3, and 7, bacterial killing progressively increased over time. There was no significant difference between the groups for S. epidermidis killing.

CONCLUSIONS AND CLINICAL IMPORTANCE

The immunomodulatory effect of noni puree may prove valuable in the future as production animal antibiotic use becomes more restricted. Additional clinical trials are warranted to investigate the clinical application of noni puree in promoting calf health.