Cyclin D1, EGFR, and Akt/mTOR pathway. Potential prognostic markers in localized laryngeal squamous cell carcinoma.

INTRODUCTION: EGFR (epidermal growth factor receptor), cyclin D1 and Akt/mTOR pathways are active in head and neck cancer. The aim of this study was to explore biomarker expression, their correlations with clinicopathological parameters and their prognostic utility in a cohort of patients with localized squamous laryngeal carcinoma. PATIENTS AND METHODS: We assessed relative messenger RNA expression of EGFR, Akt1, 2, and 3, mTOR and CCND1, copy number variants of the EGFR and CCND1 genes and immunohistochemical protein expression of EGFR, p-Akt308, p-Akt473, pmTOR, PTEN, p53 and cyclin D1 in paraffin-embedded tissue samples of localized laryngeal carcinomas. RESULTS: In 289 patients with T3-4 (77.8%), node-negative (84.1%) tumors of the larynx, high EGFR and CCND1 mRNA correlated with no or ex-smoking, (p = 0.003 and p = 0.029, respectively), while low Akt3 mRNA correlated with alcohol abuse, N0 stage, total laryngectomy, and absence of neck dissection. At a median follow-up of 74.5 months, high mTOR mRNA expression was marginally associated with shorter disease-free survival (hazard ratio [HR] = 1.54; p = 0.093) and high Akt3 mRNA with shorter overall survival (HR = 1.49; p = 0.0786), in univariate analysis. In multivariate analysis, node-positive status, subglottic-transglottic location, surgery other than total laryngectomy and mTOR/CCND1 mRNA interaction with a hazard ratio of 2.16 (p value for interaction: 0.0010) were independent predictors of relapse, while node-positive status and subglottic-transglottic location were associated with higher risk for death. CONCLUSION: In localized laryngeal cancer, clinicopathological parameters and an interaction of high mTOR and CCND1 mRNA expression were found to be associated with poor patient outcome.

HER2 gene copy number status may influence clinical efficacy to anti-EGFR monoclonal antibodies in metastatic colorectal cancer patients.

BACKGROUND: In metastatic colorectal cancer (mCRC), KRAS is the only validated biomarker used to select patients for administration of epidermal growth factor receptor (EGFR)-targeted therapies. To identify additional predictive markers, we investigated the importance of HER2, the primary EGFR dimerisation partner, in this particular disease. METHODS: We evaluated the HER2 gene status by fluorescence in situ hybridisation (FISH) in 170 KRAS wild-type mCRC patients treated with cetuximab or panitumumab. RESULTS: Depending on HER2 gene copy number status, patients showed three distinct cytogenetic profiles: 4% of patients had HER2 gene amplification (R:HER2/CEP17 ≥ 2) in all neoplastic cells (HER2-all-A), 61% of patients had HER2 gain due to polysomy or to gene amplification in minor clones (HER2-FISH+*), and 35% of patients had no or slight HER2 gain (HER2-FISH-). These subgroups were significantly correlated with different clinical behaviours, in terms of response rate (RR; P=0.0006), progression-free survival (PFS; P<0.0001) and overall survival (OS; P<0.0001). Patients with HER2-all-A profile experienced the worst outcome, patients with HER2-FISH- profile showed an intermediate behaviour and patients with HER2-FISH+* profile were related to the highest survival probability (median PFS in months: 2.5 vs 3.9 vs 7.6, respectively; median OS in months: 4.2 vs 9.7 vs 13, respectively). CONCLUSION: HER2 gene copy number status may influence the clinical response to anti-EGFR-targeted therapy in mCRC patients.

Prognostic significance of RACGAP1 mRNA expression in high-risk early breast cancer: a study in primary tumors of breast cancer patients participating in a randomized Hellenic Cooperative Oncology Group trial.

PURPOSE: RACGAP1 is a Rac GTPase-activating protein involved in cell growth regulation, cell transformation and metastasis. The aim of the present study was to explore the prognostic and/or predictive significance of RACGAP1 mRNA expression on disease-free survival (DFS) and overall survival (OS) in high-risk early breast cancer patients and compare it to that of Ki67 protein expression and to the Nottingham prognostic index (NPI). METHODS: A total of 595 high-risk breast cancer patients were treated in a two-arm trial evaluating postoperative dose-dense sequential chemotherapy with epirubicin followed by CMF with or without paclitaxel. RNA was extracted from 314 formalin-fixed paraffin-embedded primary tumor tissue samples followed by one-step quantitative RT-PCR for assessing RACGAP1 mRNA expression. RESULTS: High RACGAP1 mRNA expression (above the median) was associated with poor DFS (log-rank, p = 0.002) and OS (p < 0.001). High histological grade, as well as high Ki67 protein expression, was more frequent in the high-expression group of RACGAP1. Results of the Cox multivariate regression analysis revealed that high RACGAP1 mRNA expression independently predicted poor overall survival (Wald's p = 0.008). High Ki67 protein expression was also an adverse prognostic factor for death (p = 0.016), while high NPI score values were not. CONCLUSIONS: High RACGAP1 mRNA expression, as assessed by qRT-PCR, was found to be of adverse prognostic significance in high-risk early breast cancer patients treated with dose-dense sequential chemotherapy. The utility of RACGAP1 mRNA expression in patient selection for treatment with aggressive chemotherapy regimens should be further explored and validated in larger cohorts.

Biomarkers as a guide of medical treatment in cardiovascular diseases.

There is increasing interest in utilizing novel markers of cardiovascular disease risk and consequently, there is a need to assess the value of their use. In this paper, we will review the role of biomarkers in acute coronary syndromes, heart failure and risk stratification for cardiovascular events as guide for treatment scribing. In particular, high sensitivity assays for troponin evaluation detect with greater precision patients with elevated troponin. Therefore, direct and appropriate management is succeeded in these patients with reduction of complications due to earlier treatment, as well. Regarding heart failure, randomized trials that have evaluated biomarker guided treatment approach have not succeeded in establishing specific results for natriuretic peptides (BNP, NT-proBNP) use in terms of therapy guidance. Apart from them, a variety of novel or already used biomarkers, have been tested by small trials for heart failure management, without however, managing to dominate in every day care. Finally, as far as risk stratification for cardiovascular events is concerned, hsCRP has proved to be a strong but doubted biomarker. Therefore, lifestyle and behavioral modification remain the cornerstone of primary prevention.

Vascular endothelial growth factor polymorphisms and clinical outcome in colorectal cancer patients treated with irinotecan-based chemotherapy and bevacizumab.

The aim of the study was to evaluate the association of vascular endothelial growth factor (VEGF) genotypes with treatment efficacy in a randomized trial. This study compared two chemotherapy regimens (FOLFIRI versus XELIRI) combined with bevacizumab, as first-line treatment for metastatic colorectal cancer. DNA was extracted from blood samples of 173 patients participating in the trial. Genotyping was performed for selected SNPs (VEGF-1154, +936, -634, -2578 and -1498). All candidate genotypes were evaluated for associations with overall survival (OS), progression-free survival (PFS) and response rate (RR). There were no significant differences with respect to the distribution of genotypes in the treatment groups. The VEGF-1154 GG genotype was more frequent in patients not responding to treatment compared with responders (65.5 versus 39.8%, P = 0.032). Furthermore, the VEGF-1154 GG genotype was associated with inferior median OS compared with GA (hazards ratio = 1.68; 95% confidence interval: 1.10-2.57; P = 0.016) or with the alternative genotypes (GA and AA) combined (hazards ratio = 1.62; 95% confidence interval: 1.09-2.40; P = 0.017). In multivariate analysis, the VEGF-1154 GG genotype remained a significant adverse factor for OS. Our results support the potential predictive ability of VEGF genotypes in patients with metastatic colorectal cancer receiving irinotecan-based chemotherapy plus bevacizumab, in terms of RR and OS. However, current results should be validated prospectively, in larger cohorts.

Prognostic significance of UBE2C mRNA expression in high-risk early breast cancer. A Hellenic Cooperative Oncology Group (HeCOG) Study.

BACKGROUND: The ubiquitin-proteasome system (UPS) plays a pivotal role in tumorigenesis. Components of the UPS have recently been implicated in breast cancer progression. In the present study, we sought to explore the prognostic and/or predictive significance of UBE2C messenger RNA (mRNA) expression on disease-free survival (DFS) and overall survival (OS) in high-risk operable breast cancer patients. METHODS: Five hundred and ninety-five high-risk breast cancer patients were treated in a two-arm trial evaluating postoperative, dose-dense sequential chemotherapy with epirubicin followed by CMF (cyclophosphamide, methotrexate and 5-fluorouracil) with or without paclitaxel (Taxol). RNA was extracted from 313 formalin-fixed primary tumor tissue samples followed by one-step quantitative RT-PCR for assessment of mRNA expression of UBE2C. RESULTS: High UBE2C mRNA expression was associated with poor DFS (Wald's P = 0.003) and OS (Wald's P = 0.005). High tumor grade, as well as high Ki67 protein expression, was more frequent in the high-expression group of UBE2C. Results of the Cox multivariate regression analysis revealed that high UBE2C mRNA expression remained an independent adverse prognostic factor for relapse (P = 0.037) and death (P = 0.05). CONCLUSIONS: High UBE2C mRNA expression was found to be of adverse prognostic significance in high-risk breast cancer patients. These findings need to be validated in larger cohorts.

Triple-negative phenotype is of adverse prognostic value in patients treated with dose-dense sequential adjuvant chemotherapy: a translational research analysis in the context of a Hellenic Cooperative Oncology Group (HeCOG) randomized phase III trial.

PURPOSE: It is well recognized that breast cancer is a heterogeneous disease. The purpose of the current study was to classify patients according to the immunohistochemical phenotype of their tumors in an effort to evaluate the outcome of the respective groups of patients and specifically of those with triple-negative breast cancer (TNBC) following dose-dense sequential adjuvant chemotherapy. METHODS: A total of 595 patients with high-risk breast cancer were treated with adjuvant anthracycline-based dose-dense sequential chemotherapy with or without paclitaxel in the context of a randomized study. ER, PgR, HER2, Ki67, EGFR, and CK5 protein expression were evaluated in 298 formalin-fixed paraffin-embedded tumor samples by immunohistochemistry (IHC). HER2 was also evaluated by chromogen in situ hybridization (CISH). HER2 status and Ki67 protein expression differentiated luminal IHC subtypes (luminal B tumors being HER2 and/or Ki67-positive). RESULTS: Among the 298 tumors, the immunohistochemical panel classified 37 (12%) as luminal A, 198 (66%) as luminal B, 27 (9%) as HER2 enriched, and 36 (12%) as TNBC. The median follow-up time was 97 months. Patients with luminal A tumors had the best prognosis, with improved disease-free survival (log-rank, P = 0.033) and overall survival (P = 0.006) compared with the other three tumor subtypes. The three subtypes had an increased risk for relapse and death compared with luminal A in multivariate analysis, as well. No benefit from paclitaxel treatment was detected in any of the four subtypes or the total cohort. Hierarchical clustering based on mRNA expression of ER, PgR, and HER2 by quantitative RT-PCR identified patient groups that were comparable to the subtypes identified by IHC. CONCLUSIONS: The results of this study confirm that triple negative, luminal B and HER2-enriched phenotypes identified by IHC are of adverse prognostic value in high-risk breast cancer patients treated with dose-dense sequential adjuvant chemotherapy.

Evaluation of the association of PIK3CA mutations and PTEN loss with efficacy of trastuzumab therapy in metastatic breast cancer.

Trastuzumab (T) is effective in metastatic breast cancer (MBC) with HER2 overexpression and/or amplification, but resistance to T develops in a significant number of HER2-positive patients. Understanding the mechanisms of resistance is critical to the care of these patients. Formalin-fixed paraffin-embedded tumor tissue samples were collected from 256 patients with T-treated MBC. Clinical information was collected retrospectively from the patients' medical records. Central review of HER2 status by fluorescent in situ hybridization (FISH) and/or immunohistochemistry (IHC) revealed that of the 227 eligible patients only 139 (61%) were truly HER2-positive. PTEN, ER, PgR, and Ki67 were evaluated by IHC, while PTEN status was evaluated by FISH as well. PIK3CA mutations were identified with single nucleotide polymorphism (SNP) genotyping. Median time to progression (TTP) was 14.4 months for the HER2-positive and 10.3 for the HER2-negative patients (log-rank, P = 0.22). Survival from the initiation of T (survivalT) was 50.4 months for the HER2-positive and 35.3 for the HER2-negative subgroups (P = 0.006). Higher risk of progression was associated with HER2-positive status and the presence of PIK3CA mutations (P = 0.014). PTEN loss, as determined by IHC, was associated with lower survivalT in the whole population (P = 0.029) and in the HER2-positive population (P = 0.017). PIK3CA mutations and/or PTEN loss status were evaluated together as a single parameter, to estimate the impact of activation of the PI3K/AKT molecular pathway, and it was significantly associated with both decreased TTP (P = 0.003 in the total population, P = 0.004 in HER2-positive patients) and survival (survivalT, P = 0.011 in total, P = 0.006 in HER2-positive). In this trastuzumab-treated breast cancer population, PIK3CA activating mutations were associated with shorter TTP and PTEN loss with decreased survival. The activation of the PI3K/AKT pathway from either defect was associated with both TTP and survival, indicating the adverse effect of this pathway's status on trastuzumab efficacy.

Combination of osteopontin and activated leukocyte cell adhesion molecule as potent prognostic discriminators in HER2- and ER-negative breast cancer.

BACKGROUND: To analyse the discriminative impact of osteopontin (OPN) and activated leukocyte cell adhesion molecule (ALCAM), combined with human epidermal growth factor 2 (HER2) and oestrogen receptor (ER) in breast cancer. METHODS: Osteopontin, ALCAM, HER2 and ER mRNA expression in breast cancer tissues of 481 patients were analysed (mRNA microarray analysis, kinetic RT-PCR). Hierarchical clustering was performed in training cohort A (N=100, adjuvant treatment) and validation cohorts B (N=200, no adjuvant treatment, low-risk) and C (N=181, adjuvant treatment, high-risk). RESULTS: Negative/low ER and HER2, high OPN and low ALCAM mRNA expression helped to identify patients at particularly high risk, showing shorter DFS, P<0.001, and OAS, P=0.001. Although both validation cohorts showed diverse risk and treatment profiles, this marker constellation was concordantly associated with shorter DFS and OAS (P<0.001 and P=0.075 for cohort B and P=0.043 and P<0.001 for cohort C, respectively). In multivariate analysis, this algorithm was the main independent prognostic factor. Cohort B: DFS, P=0.0065, OAS, not significant; cohort C: DFS, P=0.026, OAS, P<0.001. CONCLUSION: Activated leukocyte cell adhesion molecule and OPN mRNA expression has a strong discriminative impact on survival within cancer patients with low or negative expression of ER and HER2, so called 'high-risk' breast cancers, and might help in identifying patients who could benefit from new treatment approaches like targeted therapies in the adjuvant setting.

Evaluation of the prognostic and predictive value of HER family mRNA expression in high-risk early breast cancer: a Hellenic Cooperative Oncology Group (HeCOG) study.

The aim of the study was to evaluate the prognostic ability of the transcriptional profiling of the HER family genes in early breast cancer, as well as to investigate the predictive value of HER2 mRNA expression for adjuvant treatment with paclitaxel. RNA was extracted from 268 formalin-fixed paraffin-embedded (FFPE) tumour tissue samples of high-risk breast cancer patients enrolled in the randomised HE10/97 trial, evaluating the effect of dose-dense anthracycline-based sequential adjuvant chemotherapy with or without paclitaxel. The mRNA expression of all four HER family members was assessed by kinetic reverse transcription-polymerase chain reaction (kRT-PCR). The overall concordance between kRT-PCR and IHC/FISH for HER2 status determination was 74%. At a median follow-up of 8 years, multivariate analysis showed that EGFR and HER2 mRNA expression was associated with reduced overall survival (OS). HER3 and HER4 mRNA level had a favourable prognostic value in terms of OS and disease-free survival (DFS), respectively. Adjusting for HER2 mRNA expression, OS and DFS did not differ between treatment groups. These data indicate that EGFR as well as HER2 are prognostic factors of worse clinical outcomes, whereas HER3 and HER4 gene transcription is associated with better prognosis in high-risk early breast cancer. However, HER2 mRNA expression did not predict clinical benefit from paclitaxel. Kinetic RT-PCR represents an alternative method for evaluating the expression of HER family members in FFPE breast carcinomas.

Plasma levels of corticotropin-releasing hormone in the inferior petrosal sinuses of healthy volunteers, patients with Cushing's syndrome, and patients with pseudo-Cushing states.

The objective of this study was to determine whether measurements of human CRH in the inferior petrosal sinuses could distinguish patients with Cushing's syndrome from those with pseudo-Cushing states or normal physiology. Twenty-five patients with Cushing's disease, 17 patients with the syndrome of ectopic ACTH, 7 patients with Cushing's syndrome of adrenal origin, 6 patients with pseudo-Cushing states, and 11 volunteers believed to have normal hypothalamic-pituitary-adrenal axes were studied. Basal plasma human CRH and ACTH were measured at two time points in the petrosal sinuses and in a peripheral vein. Most subjects were studied after the administration of intravenous diazepam or midazolam and fentanyl, but because of the known inhibitory effects of such sedation on CRH secretion, 2 normal volunteers and 3 patients with pseudo-Cushing states were studied without sedation. Human CRH levels were near or below the detection limit of the assay in all subjects. Although the normal volunteers and patients with pseudo-Cushing states who were studied without sedation had significantly greater inferior petrosal sinus ACTH levels than those who received sedation, there were no differences in measured human CRH levels for any of the groups. We conclude that inferior petrosal sinus human CRH levels are not easily measured in the inferior petrosal sinuses and cannot be used to determine whether individual patients may have hypersecretion of CRH causing their ACTH secretion.

Inferior petrosal sinus AVP in patients with Cushing's syndrome.

OBJECTIVE: In both normal volunteers and patients with Cushing's disease, one dominant inferior petrosal sinus (IPS) contains higher concentrations of AVP and ACTH than the contralateral (non-dominant) IPS, but ovine corticotrophin-releasing hormone (oCRH)-stimulated AVP in the petrosal sinuses is greater in Cushing's disease than in normal volunteers. To distinguish whether greater oCRH-releasable AVP might be specifically related to the presence of a pituitary corticotrophinoma, or be due to hypercortisolism per se, we compared IPS AVP in patients with Cushing's disease with those of patients with other causes of Cushing's syndrome. PATIENTS: Twenty-three patients with Cushing's disease, 16 patients with the syndrome of ectopic ACTH and seven patients with Cushing's syndrome of adrenal origin. MEASUREMENTS: AVP and ACTH, measured both before and 3, 5 and 10 minutes after oCRH in the petrosal sinuses, and in a peripheral vein. RESULTS: In all three groups, AVP concentrations were lateralized such that most of the AVP was found in one, dominant IPS. oCRH significantly increased IPS ACTH only in patients with Cushing's disease (p < 0.001), whereas it significantly increased dominant IPS AVP levels in all three patient groups (P < 0.01). However, neither dominant nor non-dominant IPS AVP (basal or oCRH-stimulated) were significantly different among patients with Cushing's disease, ectopic ACTH or Cushing's syndrome of adrenal origin. Basal and oCRH-stimulated IPS AVP were negatively correlated with urine free cortisol. CONCLUSIONS: Inferior petrosal sinus AVP levels are similar in all forms of Cushing's syndrome, and thus the higher inferior petrosal sinus AVP levels in patients with Cushing's disease compared with normal volunteers are unlikely to be related specifically to the presence of the pituitary corticotrophinoma. While AVP may play a role in pituitary corticotroph tumourigenesis or may be secreted by some pituitary corticotroph tumours, the observation that CRH-stimulated inferior petrosal sinus AVP levels are higher in Cushing's disease than in normal volunteers appears most likely to be related to the low endogenous CRH levels induced by hypercortisolism, rather than a consequence of Cushing's disease itself. We hypothesize that low endogenous CRH leads to increased sensitivity of central nervous system CRH receptors to exogenous CRH, and thus to greater ovine CRH-stimulated AVP.

Circadian relationships between interleukin (IL)-6 and hypothalamic-pituitary-adrenal axis hormones: failure of IL-6 to cause sustained hypercortisolism in patients with early untreated rheumatoid arthritis.

Systemic symptoms in rheumatoid arthritis (RA) are mediated, at least in part, by elevated levels of circulating interleukin (IL)-6, and this cytokine is also a potent stimulus of the hypothalamic-pituitary-adrenal axis. To evaluate the 24-h circadian secretory dynamics of ACTH, cortisol, and IL-6 and their interactions in patients with early untreated RA, we recruited and studied five newly diagnosed, untreated RA patients early in the course of their disease and five age-, gender-, and race-matched control subjects. We collected serial blood samples over 24 h and measured plasma ACTH and cortisol every 30 min and IL-6 every hour. The 24-h collection was followed by administration of ovine CRH (oCRH) and post-oCRH serial blood samples over 2 h. We analyzed the 24-h overall levels of these hormones and their circadian variations and performed time-lagged cross-correlation analyses among them. The untreated RA patients had 24 h time-integrated plasma ACTH, plasma cortisol levels, and urinary free cortisol excretion that were not significantly different from control subjects, in spite of their disease activity. However, an earlier morning surge of plasma ACTH and cortisol in the patients was suggested. Plasma ACTH and cortisol responses to oCRH were similar in RA patients and controls. IL-6 levels were significantly increased in the RA patients compared with control subjects during the early morning hours (P < 0.05). There was pronounced circadian variation of plasma Il-6 levels. In the RA patients, we detected a positive temporal correlation between plasma levels of IL-6 and ACTH/cortisol, with elevated levels of IL-6 before the elevations of ACTH and cortisol by 1 and 2 h, respectively. In the same patients, we detected a negative effect of cortisol upon IL-6 exerted with a delay of 5 h. The data presented here suggest that although endogenous IL-6 may stimulate secretion of ACTH and cortisol, overall activity of the hypothalamic-pituitary-adrenal axis remains normal and apparently is insufficient to inhibit ongoing inflammation in early untreated RA patients.

Exercise stimulates interleukin-6 secretion: inhibition by glucocorticoids and correlation with catecholamines.

In experimental animals, stress and catecholamines stimulate endogenous interleukin-6 (IL-6) secretion, whereas glucocorticoids inhibit it. To examine whether physical stress alters the secretion of IL-6 in humans, and to what extent this is correlated with catecholamines and modified by glucocorticoids, we performed high-intensity treadmill exercise test runs on 15 male volunteers, in a double-blind crossover design, after pretreatment with placebo, hydrocortisone, or dexamethasone. Plasma epinephrine and norepinephrine concentrations peaked 15 min after the start of exercise, whereas plasma IL-6 concentrations peaked twice, 15 min and 45 min after the onset of the test run. There was no difference in either the epinephrine or norepinephrine peaks among the three treatments, but the net area under the curve for IL-6 was smaller after hydrocortisone or dexamethasone than after placebo and smaller after dexamethasone than after hydrocortisone. A positive correlation was observed between peak plasma epinephrine or norepinephrine and IL-6 levels at 15 min. These findings suggest that IL-6 secretion is stimulated during exercise, possibly by catecholamines, whereas exogenous glucocorticoids attenuate this effect without affecting the catecholamine levels.

Inferior petrosal sinus arginine vasopressin concentrations in normal volunteers and patients with Cushing's disease.

In patients with Cushing's disease (CD), basal inferior petrosal sinus arginine vasopressin (AVP) concentrations are greater than peripheral levels and are further increased by the administration of CRH. AVP has an interpetrosal sinus gradient similar to that for ACTH, leading to the hypotheses that petrosal sinus AVP might either be derived from the corticotroph adenoma or be important for adenoma formation. To determine whether petrosal sinus AVP is truly increased in patients with CD, we compared inferior petrosal sinus and peripheral venous AVP and ACTH levels in 23 patients with CD and 9 healthy volunteers before and after iv ovine CRH. In both groups, AVP and ACTH showed interpetrosal lateralization, such that greater levels of both hormones were found at each time point in a single dominant petrosal sinus. When both hormones exhibited lateralization (an intersinus gradient > 1.5), ACTH and AVP always lateralized together. In patients with CD, the ACTH interpetrosal sinus lateralization correctly identified the side of the pituitary containing the tumor in 75% of evaluable patients, whereas the AVP interpetrosal sinus lateralization identified 63% (P = NS). Ovine CRH stimulated AVP in both the dominant and nondominant petrosal sinuses in patients with CD. Although basal AVP in the dominant petrosal sinus was not significantly different in patients with CD and normal volunteers (144 +/- 85 vs. 13.0 +/- 4.3 pmol/L; P = 0.058), dominant petrosal sinus AVP was significantly elevated in patients with CD compared to normal volunteers at 3 min (269 +/- 122 vs. 45.1 +/- 30.0 pmol/L; P < 0.05) and 5 min (315 +/- 120 vs 40.2 +/- 23.6 pmol/L; P < 0.05) after ovine CRH administration. Peripheral venous AVP levels were similar in all groups. We conclude that lateralization of AVP secretion occurs in both patients with CD and normal volunteers, but there is greater CRH-stimulated AVP secretion in the inferior petrosal sinuses of patients with CD.

Inferior petrosal sinus sampling in healthy subjects reveals a unilateral corticotropin-releasing hormone-induced arginine vasopressin release associated with ipsilateral adrenocorticotropin secretion.

Arginine vasopressin (AVP) acts synergistically with corticotropin-releasing hormone (CRH) to stimulate ACTH release from the anterior pituitary. In a previous study of bilateral simultaneous inferior petrosal sinus (IPS) sampling in healthy human subjects, we observed lateralized ACTH secretion, suggesting lateralized secretion of an ACTH-regulating hypothalamic factor. To investigate this possibility, we measured ACTH, CRH, AVP, and oxytocin (OT) levels in the IPS and the peripheral circulation in nine normal volunteers, before and after 1 microgram/kg i.v. bolus ovine CRH (oCRH). At baseline, ACTH, AVP, and OT exhibited a significant (P < 0.05) two to threefold intersinus gradient (ISG), indicating the existence of a dominant petrosal sinus. Endogenous CRH was undetectable in all samples. Despite similar exogenous oCRH levels in both petrosal sinuses, oCRH caused a significant increase (P < 0.001) in the ACTH ISG (15.8 +/- 5.6, mean +/- SEM), suggesting increased responsiveness of one dominant side of the anterior pituitary. This was associated with an ipsilateral CRH-induced AVP release and a significant increase (P < 0.01) in the AVP ISG (8.6 +/- 2.3), suggesting lateralized AVP secretion by the hypothalamus. Furthermore, the increased AVP ISG after oCRH correlated strongly with the ACTH ISG (r = 0.92, P < 0.01). oCRH administration did not affect OT. These findings suggest that there is a dominant petrosal sinus in healthy volunteers that appears to reflect a dominant side of the adenohypophysis, characterized by increased functional activity and/or responsiveness of the pituitary corticotrophs. This may reflect lateralized hypothalamic and/or suprahypothalamic function resulting in CRH-responsive lateralized secretion of AVP from parvocellular and/or magnocellular axons in the median eminence and the posterior pituitary. Although the functional and teleologic significance of these findings remains to be investigated, our data suggest a novel mechanism for CRH-mediated ACTH release, namely CRH-induced release of AVP which then enhances CRH action on the corticotrophs. Furthermore, our data represent the first direct evidence for the concept of brain lateralization with respect to neuroendocrine secretion.

Peripheral measures of arginine vasopressin, atrial natriuretic peptide and adrenocorticotropic hormone in premenstrual syndrome.

Because of the unique combination of physical (e.g. bloating, water retention) and psychological (e.g. mood, memory) symptoms associated with premenstrual syndrome (PMS), various hypothalamic and pituitary hormones have been implicated in the pathophysiology of PMS. We measured plasma adrenocorticotropic hormone (ACTH), arginine vasopressin (AVP) and atrial natriuretic peptide (ANP) across the menstrual cycle in 19 women with PMS and 12 normal women. AVP concentrations were lower throughout the menstrual cycle in symptomatic PMS patients compared with PMS patients during asymptomatic cycles and normal women. No differences in ACTH and ANP were observed between patients and controls. However, ACTH and ANP were positively and significantly correlated with each other in women with PMS but not in controls. These findings contribute to a growing list of menstrual cycle-independent findings in women with PMS and suggest that there may be an underlying neurobiological vulnerability that predisposes some women to experience somatic and mood dysregulation in the luteal phase of the menstrual cycle.

Hypothalamic-pituitary-adrenal axis perturbations in patients with fibromyalgia.

OBJECTIVE: To examine basal and stimulated hypothalamic-pituitary-adrenal (HPA) axis and related hormone levels, including adrenocorticotropin (ACTH), cortisol, arginine vasopressin (AVP), and neuropeptide Y (NPY), in patients with fibromyalgia (FM). METHODS: Basal and ovine corticotropin-releasing hormone (oCRH)-stimulated HPA axis function were assessed in 12 patients with FM and in age- and sex-matched normal subjects. Basal plasma AVP levels and AVP release after postural change were assessed, and plasma NPY levels were measured in the same samples. RESULTS: Patients with FM had low 24-hour urinary free cortisol, but normal peak and elevated trough plasma cortisol levels, compared with normal subjects. The net integrated ACTH response to oCRH in FM was not significantly different from that in normal subjects, but tended toward an exaggerated response. There was a significant decrease in net integrated cortisol response to oCRH in FM patients, indicating adrenal hyporesponsiveness. AVP levels were not significantly different between FM patients and control subjects, but variability was greater among the FM patients. Plasma NPY levels were significantly lower in FM patients than in normal subjects. CONCLUSION: These data support the view that HPA axis function is perturbed in patients with FM. Further study is required to ascertain the cause of HPA axis perturbations and their relationship to symptoms in patients with FM.

Exercise-induced activation of the hypothalamic-pituitary-adrenal axis: marked differences in the sensitivity to glucocorticoid suppression.

Treadmill exercise activates the hypothalamic-pituitary-adrenal axis and evokes metabolic responses proportional to exercise intensity and duration. To determine whether glucocorticoid administration would alter humoral and metabolic regulation during exercise, we administered 4 mg dexamethasone (DEX) or placebo to 11 normal, moderately trained men (19-42 yr old) in a double blinded random fashion 4 h before high intensity intermittent treadmill running. Plasma levels of ACTH, cortisol, arginine vasopressin (AVP), lactate, and glucose were measured before, during, and after exercise. A wide range of ACTH responses were seen in the DEX-treated group and arbitrarily defined as two subsets of individuals according to their responses to dexamethasone: DEX nonsuppressors and DEX suppressors. Exercise-induced increases in heart rate and circulating concentrations of cortisol, AVP, lactate, and glucose were all significantly greater (P < 0.05) in nonsuppressors (n = 4) compared to suppressors (n = 7) after both placebo and DEX administration. Interestingly, heart rate, AVP, and lactate responses were unaltered by DEX alone in both groups. In summary, this study demonstrates that normal individuals exhibit differential neuroendocrine and metabolic responses to exercise and pituitary/adrenal suppression after pretreatment with DEX. These findings reflect marked individual differences in the stress response to exercise that may derive from or lead to differential glucocorticoid negative feedback sensitivity in humans.