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Background: The adipocyte-secreted hormone adiponectin has insulin-sensitizing and anti-inflammatory properties. Although development of pancreatic cancer is associated with states of insulin resistance and chronic inflammation, the mechanistic basis of the associations is poorly understood., Methods: To determine whether prediagnostic plasma levels of adiponectin are associated with risk of pancreatic cancer, we conducted a nested case-control study of 468 pancreatic cancer case subjects and 1080 matched control subjects from five prospective US cohorts: Health Professionals Follow-up Study, Nurses' Health Study, Physicians' Health Study, Women's Health Initiative, and Women's Health Study. Control subjects were matched to case subjects by prospective cohort, year of birth, smoking status, fasting status, and month of blood draw. All samples for plasma adiponectin were handled identically in a single batch. Odds ratios were calculated with conditional logistic regression, and linearity of the association between adiponectin and pancreatic cancer was modeled with restricted cubic spline regression. All statistical tests were two-sided., Results: Median plasma adiponectin was lower in case subjects versus control subjects (6.2 vs 6.8 µg/mL, P = .009). Plasma adiponectin was inversely associated with pancreatic cancer risk, which was consistent across the five prospective cohorts (P (heterogeneity) = .49) and independent of other markers of insulin resistance (eg, diabetes, body mass index, physical activity, plasma C-peptide). Compared with the lowest quintile of adiponectin, individuals in quintiles 2 to 5 had multivariable odds ratios ([ORs] 95% confidence intervals [CIs]) of OR = 0.61 (95% CI = 0.43 to 0.86), OR = 0.58 (95% CI = 0.41 to 0.84), OR = 0.59 (95% CI = 0.40 to 0.87), and OR = 0.66 (95% CI = 0.44 to 0.97), respectively (P (trend) = .04). Restricted cubic spline regression confirmed a nonlinear association (P (nonlinearity) < .01). The association was not modified by sex, smoking, body mass index, physical activity, or C-peptide (all P (interaction) > .10)., Conclusions: In this pooled analysis, low prediagnostic levels of circulating adiponectin were associated with an elevated risk of pancreatic cancer.

Background: We conducted a phase 2b, randomised, double-blind, placebo-controlled screening trial to evaluate the addition of the multikinase inhibitor sorafenib (antiproliferative/antiangiogenic) to first-line paclitaxel for human epidermal growth factor receptor 2 (HER2)-negative locally recurrent/metastatic breast cancer., Methods: Patients were randomised to paclitaxel (90mg/m(2), weekly, intravenously, 3 weeks on/1 week off) plus sorafenib (400mg, orally, twice daily) or placebo. The primary endpoint was progression-free survival (PFS). A sample size of 220 patients was planned with relative risk ≤ 0.82 (1-sided α=0.14) after 120 events supporting a treatment effect., Findings: Patients were randomised in India (n=170), the United States (n=52) and Brazil (n=15). Median PFS was 6.9 months for sorafenib versus 5.6 months for placebo (hazard ratio (HR)=0.788; 95% confidence interval (CI), 0.558-1.112; P=0.1715 [1-sided P=0.0857]). The addition of sorafenib increased time to progression (median, 8.1 versus 5.6 months; HR=0.674; 95% CI 0.465-0.975; P=0.0343) and improved overall response (67% versus 54%; P=0.0468). Overall survival did not statistically differ (median, 16.8 versus 17.4 months; HR=1.022; 95% CI 0.715-1.461; P=0.904). Grade 3/4 toxicities (sorafenib versus placebo) included hand-foot skin reaction (31% versus 3%), neutropenia (13% versus 7%) and anaemia (11% versus 6%). Two treatment-related deaths occurred (malaria and liver dysfunction) in the sorafenib arm., Interpretation: The addition of sorafenib to paclitaxel improved disease control but did not significantly improve PFS to support a phase 3 trial of similar design. Toxicity of the combination was manageable with dose reductions., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Angiogenesis has become an important target in the treatment of several solid tumors, including breast cancer. As monotherapy, antiangiogenic agents have demonstrated limited activity in metastatic breast cancer (MBC); therefore, they have generally been developed for use in combination with chemotherapies. Thus far, the experience with antiangiogenic agents for MBC has been mixed. The results from one study assessing addition of the monoclonal antibody bevacizumab to paclitaxel led to approval of bevacizumab for MBC. However, the modest improvement of progression-free survival rates in subsequent MBC studies has led to reappraisal of bevacizumab. Phase III studies have not produced evidence supporting use of the multikinase inhibitor sunitinib alone or in combination with MBC chemotherapy. Experience with sorafenib in a phase IIb program indicates potential when used in select combinations, particularly with capecitabine; however, phase III confirmatory data are needed. Although antiangiogenic therapies combined with chemotherapy have increased progression-free survival rates for patients with MBC, increases in overall survival times have not been observed. Some studies have tried to combine antiangiogenic agents such as bevacizumab and sunitinib or sorafenib, but that approach has been limited because of toxicity concerns. Sequential use of antiangiogenic agents with differing mechanisms of action may be an effective approach. Despite setbacks, angiogenesis will likely remain an important target of treatment for selected patients with MBC.

Studies have linked prostate cancer risk with insulin resistance and obesity. Circulating levels of adiponectin, a protein involved in insulin resistance and obesity, have been associated with prostate cancer risk. We studied the association of prostate cancer risk with haplotype tagging single nucleotide polymorphisms (SNPs) of the adiponectin (ADIPOQ) and adiponectin receptor 1 (ADIPOR1) chosen based on their functional relevance or association with other types of cancer. DNA samples from 465 cases and 441 healthy volunteers from New York City were genotyped for ADIPOQ rs266729, rs822395, rs822396, rs1501299, and rs2241766 SNPs and ADIPOR1 rs12733285, rs1342387, rs7539542, rs2232853, and rs10920531 SNPs. We performed both single- and multiple-SNP analyses. We found that rs12733285, rs7539452, rs266729, rs822395, rs822396, and rs1501299 were significantly associated with prostate cancer risk. Haplotype analysis confirmed these results and identified 5 ADIPOQ 4-SNP haplotypes and 1 ADIPOR1 2-SNP haplotype tightly associated with prostate cancer risk. Importantly, 2 ADIPOQ SNPs, rs266729 and rs1501299, have been previously associated with colon and breast cancer risk, respectively, in the same direction as in this study. These findings suggest that variants of the adiponectin pathway may be associated with susceptibility to various forms of common cancers and warrant validation studies., (Copyright © 2011 Elsevier Inc. All rights reserved.)

Background: Obesity has been shown to increase breast cancer risk. FTO is a novel gene which has been identified through genome wide association studies (GWAS) to be related to obesity. Our objective was to evaluate tissue expression of FTO in breast and the role of FTO SNPs in predicting breast cancer risk., Methods: We performed a case-control study of 354 breast cancer cases and 364 controls. This study was conducted at Northwestern University. We examined the role of single nucleotide polymorphisms (SNPs) of intron 1 of FTO in breast cancer risk. We genotyped cases and controls for four SNPs: rs7206790, rs8047395, rs9939609 and rs1477196. We also evaluated tissue expression of FTO in normal and malignant breast tissue., Results: We found that all SNPs were significantly associated with breast cancer risk with rs1477196 showing the strongest association. We showed that FTO is expressed both in normal and malignant breast tissue. We found that FTO genotypes provided powerful classifiers to predict breast cancer risk and a model with epistatic interactions further improved the prediction accuracy with a receiver operating characteristic (ROC) curves of 0.68., Conclusion: In conclusion we have shown a significant expression of FTO in malignant and normal breast tissue and that FTO SNPs in intron 1 are significantly associated with breast cancer risk. Furthermore, these FTO SNPs are powerful classifiers in predicting breast cancer risk., (© 2011 Kaklamani et al; licensee BioMed Central Ltd.)

Lapatinib is an oral dual erbB 1/2 tyrosine kinase inhibitor that inhibits human EGF receptor 2 (HER2) and blocks the EGF receptor. Studies have shown that in patients with metastatic HER2-positive breast cancer that is resistant to trastuzumab, the addition of lapatinib to capecitabine improves progression-free survival and appears to lengthen overall survival. Furthermore, lapatinib has been studied in patients with involvement of the CNS and has been associated with stable disease and some responses. Its combination with letrozole provided an improvement in progression-free survival compared with single-agent letrozole in women with hormone receptor-positive, HER2-positive metastatic breast cancer. More recently, data suggested that the combination of lapatinib with trastuzumab significantly improves overall survival in women with metastatic breast cancer compared with single-agent lapatinib. Current indications in the USA for the use of lapatinib are for the treatment of metastatic HER2-positive breast cancer, both in combination with capecitabine in patients who have received taxane, anthracycline and traztuzumab, and in combination with letrozole for postmenopausal patients with hormone receptor- and HER2-overexpressing breast cancer. Common side effects of lapatinib include diarrhea and rash. Studies to date have found a less than 2% risk for cardiotoxicity, although most cardiac events that occurred during the studies were not attributed to lapatinib. It is important to consider that most of the patients in existing studies had already been treated with trastuzumab with no significant cardiotoxicity; therefore, future studies will show how trastuzumab-naive patients tolerate lapatinib. Ongoing research is evaluating the role of lapatinib in the adjuvant setting as a single agent or in combination with trastuzumab.

Purpose: Constitutively decreased TGFBR1 allelic expression is emerging as a potent modifier of colorectal cancer risk in mice and humans. This phenotype was first observed in mice, then in lymphoblastoid cell lines from patients with microsatellite stable colorectal tumors., Patients and Methods: We assessed the frequency of constitutively decreased TGFBR1 allelic expression and association with SNPs covering the TGFBR1 locus using RNA and DNA extracted from the peripheral blood lymphocytes of 118 consecutive patients with biopsy-proven adenocarcinoma of the colon or the rectum., Results: We found that 11(9.3%) of 118 patients exhibited decreased TGFBR1 allelic expression (TGFBR1 ASE). TGFBR1 ASE was strongly associated with three SNPs in linkage disequilibrium with each other: rs7034462 (p = 7.2 x 10-4), TGFBR1*6A (p = 1.6 x 10-4) and rs11568785 (p = 1.4 x 10-4)., Conclusion: These results confirm the high prevalence of constitutively decreased TGFBR1 allelic expression among patients with colorectal cancer. The association of this phenotype with TGFBR1*6A, rs7034462 and rs1156875 suggests an association between TGFBR1 SNPs and colorectal cancer, which warrants additional studies.

Cathepsin D is a lysosomal hydrolase involved in intra- and extracellular proteolysis. This enzyme is aberrantly produced and processed in malignancy, and most notably is over-secreted into the tumor cell microenvironment. This hyper-secretion may lead to excessive degradation of the extracellular matrix, and contribute to tumor progression and metastases. These phenomena have been established in vitro, and there is evidence that Cathepsin D is similarly dysregulated in human breast cancer patients. Because breast cancer lacks an effective screening or surveillance biomarker, here we address the hypothesis that serum Cathepsin D activity may be useful to assess the presence or progression of breast cancer in females. While representative histologic sections from various disease-specific cohorts confirm previous findings that increased Cathepsin D production and secretion correlate with tumor progression, we report no difference in serum Cathepsin D activity between patients who are disease free, patients with pre-invasive or limited invasive disease, and patients with metastatic disease. Furthermore, in patients with known metastatic disease, there were no clinical variables associated with significantly different serum Cathepsin D activity. However, the immunohistochemical localization of Cathepsin D expression in histopathologic sections from breast cancer patients correlates with disease progression. Based on the serum results, and in contradistinction to Cathepsin D localization in breast cancer tissues, our findings support using Cathepsin D as a reliable histopathology biomarker for disease progression, but not for serum screening.

Background: The transforming growth factor beta-1 gene (TGFB1) is a plausible candidate for breast cancer susceptibility. The L10P variant of TGFB1 is associated with higher circulating levels and secretion of TGF-beta, and recent large-scale studies suggest strongly that this variant is associated with breast cancer risk in the general population., Methods: To evaluate whether TGFB1 L10P also modifies the risk of breast cancer in BRCA1 or BRCA2 mutation carriers, we undertook a multi-center study of 3,442 BRCA1 and 2,095 BRCA2 mutation carriers., Results: We found no evidence of association between TGFB1 L10P and breast cancer risk in either BRCA1 or BRCA2 mutation carriers. The per-allele HR for the L10P variant was 1.01 (95%CI: 0.92-1.11) in BRCA1 carriers and 0.92 (95%CI: 0.81-1.04) in BRCA2 mutation carriers., Conclusions: These results do not support the hypothesis that TGFB1 L10P genotypes modify the risk of breast cancer in BRCA1 or BRCA2 mutation carriers.

TGFBR1*6A is a common hypomorphic variant of the type I transforming growth factor (TGF)-beta receptor (TGFBR1), which transduces TGF-beta growth inhibitory signals less effectively than TGFBR1. Recent studies suggest that TGFBR1*6A confers a selective growth advantage to both normal appearing and cancerous epithelial cells in the presence of TGF-beta. We have previously shown that TGFBR1*6A is somatically acquired in head and neck and colon cancer (10). Using microdissected tissues, we show that TGFBR1*6A is somatically acquired by stromal and epithelial cells adjacent to colorectal and head and neck tumors. Somatic acquisition of the TGFBR1*6A allele is not accompanied by acquisition of other tumor-specific mutations. Furthermore, lymphocytes located within the stroma or the normal appearing epithelium do not have evidence of TGFBR1*6A acquisition. The highest TGFBR1*6A/TGFBR1 allelic ratio is observed at the tumor's edge, and traces of TGFBR1*6A are detected as far as 2 cm away from the tumor, which is suggestive of centrifugal spread of cells that harbor TGFBR1*6A. Assessment of CDH1 and CDH2 expression does not indicate epithelial-mesenchymal transformation. The results suggest that TGFBR1*6A somatic acquisition is a critical event in the early stages of cancer development that is associated with field cancerization. They also represent the first human report of somatically acquired altered stromal TGF-beta signaling during oncogenesis and the first report of a concordant mutation in the stromal and epithelial compartments in colon cancer.

Purpose: To present data from patients with breast cancer liver metastases who underwent radioembolization with yttrium (90Y) microspheres., Materials and Methods: Using standard 90Y lobar treatment protocol, 27 female patients with progressing liver metastases on standard of care polychemotherapy were treated under an open-label phase 2 protocol. After treatment, we assessed (a) tumor response using computed tomography and/or positron emission tomography, (b) biochemical toxicity, and (c) survival., Results: The mean age of the patients was 52. Seventeen (63%) patients received 20 left lobe treatments (median radiation dose, 123 Gy; mean, 119 Gy), and 20 (74%) patients received 22 right lobe treatments (median radiation dose, 121 Gy; mean, 109 Gy) to the treatment site. No significant dose-difference was noted between the two lobes (P=.69). Tumor response on 90-day follow-up computed tomography showed (a) complete and partial response in nine (39.1%) patients, (b) stable disease in 12 (52.1%) patients, and (c) progressive disease in 2 (8.8%) patients. Positive tumor response on positron emission tomography was noted in 17 (63%) patients. Three of 27 (11%) patients (Eastern Cooperation Oncology Group 1, 2, or 3) showed bilirubin toxicity of grade 3, all of which were attributed to disease progression. Median survival for Eastern Cooperation Oncology Group 0 versus 1, 2, or 3 patients was 6.8 months and 2.6 months, respectively (P=.24) and for patients with tumor burden<25% versus >25% was 9.4 and 2.0 months, respectively (P=.46)., Conclusions: Radioembolization with 90Y brachytherapy device may be a viable therapeutic option for the treatment of breast cancer liver metastases in patients who have progressed or failed on standard of care polychemotherapy.

Opinion Statement: The combined observation that 20-30% of all patients with breast cancer have a family history of the disease and the results from twin studies showing that 25% of breast cancer cases are heritable, indicate that this malignancy is one of the most commonly inherited cancers. Discovery of the BRCA1 and BRCA2 genes more than a decade ago has had a tremendous impact on patient care allowing for early detection and prevention of breast cancer. However, deleterious mutations within the BRCA1 and BRCA2 genes cause at most 3-8% of all breast cancer cases. New data indicate that genomic rearrangements within the same genes may occasionally identify additional carriers of nonfunctional BRCA1 and BRCA2 genes. Such genomic rearrangements are missed by conventional sequencing. The remainder of the unexplained familial risk is presumably due to other yet unidentified high penetrance genes, but polygenic mechanisms and high frequency low penetrance tumor susceptibility genes are likely to account for a greater proportion of familial breast cancers. In this regard, there is growing evidence that a common variant of the type I TGF-ss receptor, TGFBR1*6A, may account for approximately 5% of all breast cancer cases, a fraction similar to that attributable to BRCA1 and BRCA2. Such genes may also modify the penetrance of the BRCA1 and BRCA2 genes. In the next decade, screening for combinations of high and low penetrance genes will likely permit the identification of a large fraction of inherited breast cancer cases and will further reduce the burden of familial breast cancer.

We now recognize that not all breast cancers are the same. Different characteristics in gene expression profiles result in differential clinical behavior. With the use of gene microarrays, different subtypes of breast cancer have been characterized. These subtypes include the basal, the ERBB2+, and the luminal A, B and C subtypes. The importance of these different subtypes lies in the fact that they differ in clinical outcome, with the basal and ERBB2+ subtypes having the worst prognosis and the luminal A group having the best prognosis. However, identification of these subtypes is still not clinically used. Other strategies for evaluating tumors in a clinical setting have been developed using smaller sets of genes. One such strategy is the 21-gene assay (Oncotype DX), which is currently in commercial use in the USA. One advantage of this test is the use of paraffin-embedded blocks instead of previous methods, which required fresh frozen tissue. Oncotype DX has been shown to predict 10-year distant recurrence in patients with estrogen receptor-positive, axillary lymph node-negative breast cancer. This genomic assay has also been shown to predict chemotherapy and endocrine therapy response. Large, prospective, randomized clinical trials are currently underway using this genomic test. Other similar tests are also finding their way in clinical practice. A 70-gene assay, which has been developed by a group in The Netherlands, is currently being used as a tool to assign treatment in women with early stage breast cancer. In the near future, clinical decisions will most likely be dictated by the genetic characteristics of the tumor, with the clinical characteristics becoming less important. Tailoring our treatment based on individual tumor characteristics will help us develop better therapeutic strategies and save many of our patients from receiving unnecessary toxic therapy.

Context: TGFBR1*6A is a common polymorphism of the type I transforming growth factor beta receptor (TGFBR1). Epidemiological studies suggest that TGFBR1*6A may act as a tumor susceptibility allele. How TGFBR1*6A contributes to cancer development is largely unknown., Objectives: To determine whether TGFBR1*6A is somatically acquired by primary tumors and metastases during cancer development and whether the 3-amino acid deletion that differentiates TGFBR1*6A from TGFBR1 is part of the mature receptor or part of the signal sequence and to investigate TGFBR1*6A signaling in cancer cells., Design, Setting, and Patients: Tumor and germline tissues from 531 patients with a diagnosis of head and neck, colorectal, or breast cancer recruited from 3 centers in the United States and from 1 center in Spain from June 1, 1994, through June 30, 2004. In vitro translation assays, MCF-7 breast cancer cells stably transfected with TGFBR1*6A, TGFBR1, or the vector alone, DLD-1 colorectal cancer cells that endogenously carry TGFBR1*6A, and SW48 colorectal cancer cells that do not carry TGFBR1*6A., Main Outcome Measures: TGFBR1*6A somatic acquisition in cancer. Determination of the amino terminus of the mature TGFBR1*6A and TGFBR1 receptors. Determination of TGF-beta-dependent cell proliferation., Results: TGFBR1*6A was somatically acquired in 13 of 44 (29.5%) colorectal cancer metastases, in 4 of 157 (2.5%) of colorectal tumors, in 4 of 226 (1.8%) head and neck primary tumors, and in none of the 104 patients with breast cancer. TGFBR1*6A somatic acquisition is not associated with loss of heterozygosity, microsatellite instability, or a mutator phenotype. The signal sequences of TGFBR1 and TGFBR1*6A are cleaved at the same site resulting in identical mature receptors. TGFBR1*6A may switch TGF-beta growth inhibitory signals into growth stimulatory signals in MCF-7 breast cancer cells and in DLD-1 colorectal cancer cells., Conclusions: TGFBR1*6A is somatically acquired in 29.5% of liver metastases from colorectal cancer and may bestow cancer cells with a growth advantage in the presence of TGF-beta. The functional consequences of this conversion appear to be mediated by the TGFBR1*6A signal sequence rather than by the mature receptor. The results highlight a new facet of TGF-beta signaling in cancer and suggest that TGFBR1*6A may represent a potential therapeutic target in cancer.

Purpose: TGFBR16A is a tumor susceptibility gene that increases breast, colon, and ovarian cancer risk. Fourteen percent of the general population carries TGFBR16A, and TGFBR16A homozygotes have a greater than 100% increased colon cancer risk compared with noncarriers. Low-penetrance genes such as TGFBR16A may account for a sizable proportion of familial colorectal cancer occurrences. To test this hypothesis, we determined whether TGFBR16A contributes to a proportion of mismatch repair (MMR) gene mutation-negative hereditary nonpolyposis colorectal cancer (HNPCC) patients., Patients and Methods: A case-case study was performed of 208 index patients with HNPCC meeting the Amsterdam criteria. Patients were examined for mutations and genomic rearrangements in the MLH1, MSH2, and MSH6 genes and genotyped for TGFBR16A. Tumor microsatellite instability status was available for 95 patients., Results: A total of 144 patients (69.2%) carried a deleterious mutation and were classified as positive for MMR gene mutation; 64 patients (30.8%) had no evidence of mutations and were classified as MMR negative. TGFBR16A allelic frequency was significantly higher among MMR-negative patients (0.195) than among MMR-positive patients (0.104; P = .011). The proportion of TGFBR16A homozygotes was nine-fold higher among MMR-negative (6.3%) than among MMR-positive patients (0.7%; P = .032). The highest TGFBR16A allelic frequency was found among MMR-negative patients with tumors exhibiting no microsatellite instability (0.211), and the lowest frequency was found among MMR-positive patients with tumors exhibiting microsatellite instability (0.121); the difference was not statistically significant (P = .17)., Conclusion: TGFBR16A may be causally responsible for a proportion of HNPCC occurrences.

Prostate cancer is the most commonly diagnosed cancer in men and one of the leading causes of cancer deaths. There is strong genetic evidence indicating that a large proportion of prostate cancers are caused by heritable factors but the search for prostate cancer susceptibility genes has thus far remained elusive. TGFBR1*6A, a common hypomorphic variant of the type I Transforming Growth Factor Beta receptor, is emerging as a tumor susceptibility allele that predisposes to the development of breast, colon and ovarian cancer. The association with prostate cancer has not yet been explored. A total of 907 cases and controls from New York City were genotyped to test the hypothesis that TGFBR1*6A may contribute to the development of prostate cancer. TGFBR1*6A allelic frequency among cases (0.086) was slightly higher than among controls (0.080) but the differences in TGFBR1*6A genotype distribution between cases and controls did not reach statistical significance (p = 0.67). Our data suggest that TGFBR1*6A does not contribute to the development of prostate cancer.

Targeted therapy for breast cancer has existed since 1986, when Beatson published his observations on oophorectomy. In the past 5 years monoclonal antibodies and tyrosine kinase inhibitors have been evaluated in phase I and II clinical trials of breast cancer. Trastuzumab (Herceptin; Genentech, Inc, South San Francisco, CA) was the first such agent to be approved by the US Food And Drug Administration, following findings that it improved survival in patients with metastatic breast cancer. Gefitinib (ZD1839, Iressa; AstraZeneca, Wilmington, DE) has little activity as a single agent in unselected patients, but, preclinical data have suggested synergy with tamoxifen and other hormonal agents, as well as other growth factor inhibitors. Bevacizumab (Avastin; Genentech, Inc), a monoclonal antibody against vascular endothelial growth factor is being evaluated in metastatic breast cancer. Furthermore, agents targeting other pathways, such as the Ras pathway with farnesyl transferase inhibitors, and mTOR with rapamycin analogues are currently under investigation. In the next few years, and as trials with the above agents mature, we will further define the role of these targeted agents in the treatment of breast cancer.

Purpose: Behçet's disease (BD) is known to be associated with HLA-B51 in many different ethnic groups. Recently MICA, a member of a novel family of the human major histocompatibility complex (MHC) class I genes termed MIC (MHC class I chain-related genes), was identified near the HLA-B gene, and a triplet repeat microsatellite polymorphism was found in the transmembrane (TM) region. Because a strong association with BD of one particular MICA-TM allele, A6, was shown in a Japanese population, the present study was conducted to investigate microsatellite polymorphism in Greek patients with BD to know whether this association is generally observed in BD occurring in other populations., Methods: Thirty-eight Greek patients with BD and 40 ethnically matched control subjects were examined for MICA microsatellite polymorphism using polymerase chain reaction (PCR) and subsequent automated fragment detection by fluorescent-based technology., Results: Similar to the Japanese patients with BD, the phenotype frequency of the MICA-TM A6 allele was significantly increased in the Greek patients with BD (50.0% in control subjects versus 86.8% in BD cases), with an odds ratio (OR) of 6.60 (P = 0.0012). The MICA-A6 allele was found in a high frequency both in males and females (weighted OR = 6.68; P = 0.0017). No association was found between the A6 allele and several disease features. A strong association exists between the MICA-TM A6 allele and the B*5101 allele in both the control subjects and patients with BD (weighted OR = 44.39; P = 0.0000023)., Conclusions: This study revealed in Greek patients a strong association of BD with a particular MICA-TM allele, MICA-A6, providing insight into the molecular mechanism underlying the development of BD.

Leptin, a product of fat cells, provides a signal of nutritional status to the central nervous system. Leptin concentrations have ultradian and diurnal fluctuations. We conducted this study to assess sex differences in the levels of organization of frequently sampled leptin concentrations in healthy, normal weight women and men. Leptin levels were sampled every 7 min for 24 h in 14 healthy, normal weight individuals (6 women and 8 men). The 14 leptin time series containing a total of 2898 leptin measurements were assessed by 1) algorithms that characterize statistically significant pulsatility, 2) Spectral (Fourier) analysis, 3) analysis of time intervals and variability, and 4) approximate entropy. We found that frequently sampled plasma leptin concentrations have a 24-h profile that is numerically more than twice as high in women as in men, and leptin pulse amplitude is likewise more than twice as high in women. However, healthy men and women have nearly identical concentration-independent and frequency-related 24-h and ultradian patterns. Leptin concentrations have nonrandom fluctuations over 24 h, independent of their absolute value and underlying 24-h periodicity, that are similar in men and women. Ultradian periodicities detected by Fourier time series have similar values in men and women. The strongest distinction between the sexes in the level of organization of leptin concentration is not at the level of pulse organization or oscillation frequency, but, rather, in the mass or amount of leptin released (or removed) per unit time, indicating that women might be more resistant to the effects of leptin than men. Because leptin is clinically relevant to the regulation of body weight, future studies should examine whether the relative leptin resistance exhibited by women might contribute to their increased susceptibility to disorders whose pathophysiology involves dysregulation of food intake and body weight.

Leptin, an adipocyte hormone, is a trophic factor for the reproductive system; however, it is still unknown whether there is a dynamic relation between fluctuations in circulating leptin and hypothalamic-pituitary-ovarian (HPO) axis hormones. To test the hypothesis that fluctuations in plasma leptin concentrations are related to the levels of luteinizing hormone (LH) and estradiol, we sampled plasma from six healthy women every 7 min for 24 h during days 8-11 of the menstrual cycle. Cross-correlation analysis throughout the 24-h cycle revealed a relation between release patterns of leptin and LH, with a lag of 42-84 min but no significant cross-correlation between LH and estradiol. The ultradian fluctuations in leptin levels showed pattern synchrony with those of both LH and estradiol as determined by cross-approximate entropy (cross-ApEn). At night, as leptin levels rose to their peak, the pulsatility profiles of LH changed significantly and became synchronous with those of leptin. LH pulses were fewer, of longer duration, higher amplitude, and larger area than during the day. Moreover, the synchronicity of LH and leptin occurred late at night, at which time estradiol and leptin also exhibited significantly stronger pattern coupling than during the day. We propose that leptin may regulate the minute-to-minute oscillations in the levels of LH and estradiol, and that the nocturnal rise in leptin may determine the change in nocturnal LH profile in the mid-to-late follicular phase that precedes ovulation. This may explain the disruption of hypothalamic-pituitary-ovarian function that is characteristic of states of low leptin release, such as anorexia nervosa and cachexia.

The expression of leptin, an adipocyte-derived protein whose circulating levels reflect energy stores, can be induced by tumor necrosis factor (TNF)alpha in rodents, but an association between the TNF alpha system and leptin levels has not been reported in humans. To evaluate the potential association between serum leptin and the TNF alpha system, we measured the levels of soluble TNF alpha-receptor (sTNF alpha-R55), which has been validated as a sensitive indicator of activation of the TNF alpha system. We studied two groups: 1) 82 young healthy normal controls and 2) 48 patients with noninsulin dependent diabetes mellitus (NIDDM) and 24 appropriately matched controls. By simple regression analysis in controls, there was a strong positive association between leptin and 3 parameters: body mass index, sTNF alpha-R55, and insulin levels. In a multiple regression analysis model, leptin remained significantly and strongly associated with body mass index, and the association of leptin with both insulin and sTNF alpha-R55, although weakened, remained significant. Patients with NIDDM had leptin concentrations similar to controls of similar weight. Importantly, serum levels of sTNF alpha-R55 were also positively and independently associated with leptin in this group of diabetic subjects and matched controls. These data are consistent with the hypothesis that the TNF alpha system plays a role in regulating leptin levels in humans. Further elucidation of a possible role of the TNF alpha system in leptin expression and circulating levels may have important implications for our understanding of obesity and cachexia in humans.

The association of certain HLA-DRB1 alleles in Green rheumatoid arthritis (RA) patients with several features of the disease, the gender of the patient and the age at onset was investigated. This case control study includes 86 Greek RA patients and 130 healthy controls unrelated to the patients. HLA typing was performed by polymerase chain reaction (PCR) and hybridization with sequence-specific oligonucleotide (SSO) probes. HLA-DR4 was significantly increased in RA patients. The alleles *0101, *0401, *0405 and *1001 were associated with a higher risk of RA. The *0408 allele was absent from our patients. Sixty-five per cent of RA patients carried the 'sharp epitope' (SE) compared with 31.5% of controls. The risk for RA in individuals carrying a single allele positive for SE was 2.85 times higher, and for those carrying two alleles positive for SE 8.57 times higher, than in SE-negative individuals. The risk was higher in those carrying the *0401 allele, followed by *0405 and *0101, while the genotype *0401/*0404 was absent. Alleles positive for SE comprise a predisposing factor for RA at an early age, particularly in men, and are associated with positive rheumatoid factor, nodules and erosions.