Effects of lixisenatide treatment on mild cachexia and related metabolic abnormalities in Walker-256 tumour-bearing rats.

Lixisenatide, a glucagon-like peptide-1 (GLP-1) receptor agonist, is used in the treatment of type 2 diabetes mellitus (T2DM). It increases insulin (INS) secretion and can decrease INS resistance, improving metabolic disorders in this disease. However, its effects on metabolic disturbances in cancer-bearing, which also exhibit decreased INS secretion and INS resistance, changes that may contribute to weight loss (cachexia), have not yet been evaluated. The purpose of this study was to investigate the lixisenatide treatment effects on mild cachexia and related metabolic abnormalities in Walker-256 tumour-bearing rats. Lixisenatide (50 µg kg-1 , SC) was administered once daily, for 6 days, after inoculation of Walker-256 tumour cells. Acute lixisenatide treatment did not improve hypoinsulinemia, INS secretion and INS resistance of tumour-bearing rats. It also did not prevent the reduced glucose and increased triacylglycerol and lactate in the blood and nor the loss of retroperitoneal and epididymal fat of these animals. However, acute lixisenatide treatment accentuated the body mass loss of tumour-bearing rats. Therefore, lixisenatide, unlike T2DM, does not improve hypoinsulinemia and INS resistance associated with cancer, evidencing that it does not have the same beneficial effects in these two diseases. In addition, lixisenatide aggravated weight loss of tumour-bearing rats, suggesting that its use for treatment of T2DM patients with cancer should be avoided. SIGNIFICANCE OF THE STUDY: Lixisenatide increases insulin secretion and appears to reduce insulin resistance in T2DM. However, lixisenatide treatment does not improve hypoinsulinemia and insulin resistance associated with cancer, as it does in T2DM, and aggravated weight loss, suggesting that its use for treatment of T2DM patients with cancer should be avoided.

Penetrance of the TP53 R337H Mutation and Pediatric Adrenocortical Carcinoma Incidence Associated with Environmental Influences in a 12-Year Observational Cohort in Southern Brazil.

The TP53 R337H mutation is associated with increased incidence of pediatric adrenocortical tumor (ACT). The different environmental conditions where R337H carriers live have not been systematically analyzed. Here, the R337H frequencies, ACT incidences, and R337H penetrance for ACT were calculated using the 2006 cohort with 4165 R337H carriers living in Paraná state (PR) subregions. The effectiveness of a second surveillance for R337H probands selected from 42,438 tested newborns in PR (2016 cohort) was tested to detect early stage I tumor among educated families without periodical exams. Estimation of R337H frequencies and ACT incidence in Santa Catarina state (SC) used data from 50,115 tested newborns without surveillance, ACT cases from a SC hospital, and a public cancer registry. R337H carrier frequencies in the population were 0.245% (SC) and 0.306% (PR), and 87% and 95% in ACTs, respectively. The ACT incidence was calculated as ~6.4/million children younger than 10 years per year in PR (95% CI: 5.28; 7.65) and 4.15/million in SC (CI 95%: 2.95; 5.67). The ACT penetrance in PR for probands followed from birth to 12 years was 3.9%. R337H carriers living in an agricultural subregion (C1) had a lower risk of developing pediatric ACT than those living in industrial and large urban subregion (relative risk = 2.4). One small ACT (21g) without recurrence (1/112) was detected by the parents in the 2016 cohort. ACT incidence follows R337H frequency in each population, but remarkably environmental factors modify these rates.

Pyrrolidine dithiocarbamate inhibits mouse acute kidney injury induced by diclofenac by targeting oxidative damage, cytokines and NF-κB activity.

AIMS: Non-steroidal anti-inflammatory drugs (NSAIDs) are widely used and effective anti-inflammatories despite the well-known side effects such as gastrointestinal damage, acute kidney injury (AKI), and cardiovascular dysfunctions. Diclofenac is among the most prescribed NSAIDs due to its efficient analgesic and anti-inflammatory properties. Patients using diclofenac possess 77% risk increase to develop AKI. Activation of NF-κB contributes to diclofenac-induced AKI, which is in line with the use of glucocorticoids as one of the management choices to treat AKI patients. MAIN METHODS: In this work, we investigate the efficacy of pyrrolidine dithiocarbamate (PDTC) in diclofenac-induced AKI in mice given it is a known NF-κB inhibitor. KEY FINDINGS: We observed that diclofenac increased proteinuria and urine neutrophil gelatinase-associated lipocalin (NGAL), blood levels of urea, creatinine, oxidative stress, C-reactive protein (CRP), and pro-inflammatory cytokine after 24 h of a bolus administration. In renal tissue, diclofenac also induced morphological changes consistent with kidney damage, modulated cytokine production, increased oxidative stress and reduced antioxidant defenses. These alterations induced by diclofenac were accompanied by activation of NF-κB in the kidney. Treatment with PDTC dose-dependently reduced diclofenac-induced blood urea, creatinine, and oxidative stress. In addition, PDTC reduced proteinuria and urine NGAL levels and blood CRP and pro-inflammatory cytokines. In the kidney, PDTC inhibited diclofenac-induced morphological changes, pro-inflammatory cytokine production, oxidative stress, and NF-κB activation, and increased antioxidant defenses and anti-inflammatory cytokine IL-10. SIGNIFICANCE: Our data demonstrate that PDTC ameliorates diclofenac-induced AKI and that targeting NF-κB signaling pathway is a promising therapeutic approach for the treatment of diclofenac-induced AKI.

Vinpocetine reduces diclofenac-induced acute kidney injury through inhibition of oxidative stress, apoptosis, cytokine production, and NF-κB activation in mice.

Acute kidney injury (AKI) represents a complex clinical condition associated with significant morbidity and mortality. Approximately, 19-33% AKI episodes in hospitalized patients are related to drug-induced nephrotoxicity. Although, considered safe, non-steroidal anti-inflammatory drugs such as diclofenac have received special attention in the past years due to the potential risk of renal damage. Vinpocetine is a nootropic drug known to have anti-inflammatory properties. In this study, we investigated the effect and mechanisms of vinpocetine in a model of diclofenac-induced AKI. We observed that diclofenac increased proteinuria and blood urea, creatinine, and oxidative stress levels 24h after its administration. In renal tissue, diclofenac also increased oxidative stress and induced morphological changes consistent with renal damage. Moreover, diclofenac induced kidney cells apoptosis, up-regulated proinflammatory cytokines, and induced the activation of NF-κB in renal tissue. On the other hand, vinpocetine reduced diclofenac-induced blood urea and creatinine. In the kidneys, vinpocetine inhibited diclofenac-induced oxidative stress, morphological changes, apoptosis, cytokine production, and NF-κB activation. To our knowledge, this is the first study demonstrating that diclofenac-induced AKI increases NF-κB activation, and that vinpocetine reduces the nephrotoxic effects of diclofenac. Therefore, vinpocetine is a promising molecule for the treatment of diclofenac-induced AKI.

A boy with Prader-Willi syndrome: unmasking precocious puberty during growth hormone replacement therapy.

Prader-Willi syndrome (PWS) is a genetic disorder frequently characterized by obesity, growth hormone deficiency, genital abnormalities, and hypogonadotropic hypogonadism. Incomplete or delayed pubertal development as well as premature adrenarche are usually found in PWS, whereas central precocious puberty (CPP) is very rare. This study aimed to report the clinical and biochemical follow-up of a PWS boy with CPP and to discuss the management of pubertal growth. By the age of 6, he had obesity, short stature, and many clinical criteria of PWS diagnosis, which was confirmed by DNA methylation test. Therapy with recombinant human growth hormone (rhGH) replacement (0.15 IU/kg/day) was started. Later, he presented psychomotor agitation, aggressive behavior, and increased testicular volume. Laboratory analyses were consistent with the diagnosis of CPP (gonadorelin-stimulated LH peak 15.8 IU/L, testosterone 54.7 ng/dL). The patient was then treated with gonadotropin-releasing hormone analog (GnRHa). Hypothalamic dysfunctions have been implicated in hormonal disturbances related to pubertal development, but no morphologic abnormalities were detected in the present case. Additional methylation analysis (MS-MLPA) of the chromosome 15q11 locus confirmed PWS diagnosis. We presented the fifth case of CPP in a genetically-confirmed PWS male. Combined therapy with GnRHa and rhGH may be beneficial in this rare condition of precocious pubertal development in PWS.

A boy with Prader-Willi syndrome: unmasking precocious puberty during growth hormone replacement therapy

SUMMARY Prader-Willi syndrome (PWS) is a genetic disorder frequently characterized by obesity, growth hormone deficiency, genital abnormalities, and hypogonadotropic hypogonadism. Incomplete or delayed pubertal development as well as premature adrenarche are usually found in PWS, whereas central precocious puberty (CPP) is very rare. This study aimed to report the clinical and biochemical follow-up of a PWS boy with CPP and to discuss the management of pubertal growth. By the age of 6, he had obesity, short stature, and many clinical criteria of PWS diagnosis, which was confirmed by DNA methylation test. Therapy with recombinant human growth hormone (rhGH) replacement (0.15 IU/kg/day) was started. Later, he presented psychomotor agitation, aggressive behavior, and increased testicular volume. Laboratory analyses were consistent with the diagnosis of CPP (gonadorelin-stimulated LH peak 15.8 IU/L, testosterone 54.7 ng/dL). The patient was then treated with gonadotropin-releasing hormone analog (GnRHa). Hypothalamic dysfunctions have been implicated in hormonal disturbances related to pubertal development, but no morphologic abnormalities were detected in the present case. Additional methylation analysis (MS-MLPA) of the chromosome 15q11 locus confirmed PWS diagnosis. We presented the fifth case of CPP in a genetically-confirmed PWS male. Combined therapy with GnRHa and rhGH may be beneficial in this rare condition of precocious pubertal development in PWS.

Rapid and Complete Remission of Metastatic Adrenocortical Carcinoma Persisting 10 Years After Treatment With Mitotane Monotherapy: Case Report and Review of the Literature.

Mitotane has been used for more than 5 decades as therapy for adrenocortical carcinoma (ACC). However its mechanism of action and the extent of tumor response remain incompletely understood. To date no cases of rapid and complete remission of metastatic ACC with mitotane monotherapy has been reported. A 52-year-old French Canadian man presented with metastatic disease 2 years following a right adrenalectomy for stage III nonsecreting ACC. He was started on mitotane which was well tolerated despite rapid escalation of the dose. The patient course was exceptional as he responded to mitotane monotherapy after only few months of treatment. Initiation of chemotherapy was not needed and he remained disease-free with good quality of life on low maintenance dose of mitotane during the following 10 years. A germline heterozygous TP53 exon 4 polymorphism c.215C>G (p. Pro72Arg) was found. Immunohistochemical stainings for IGF-2 and cytoplasmic ß-catenin were positive. Advanced ACC is an aggressive disease with poor prognosis and the current therapeutic options remain limited. These findings suggest that mitotane is a good option for the treatment of metastatic ACC and might result in rapid complete remission in selected patients.

Basal and Post-ACTH Aldosterone and Its Ratios Are Useful During Adrenal Vein Sampling in Primary Aldosteronism.

CONTEXT: Adrenal vein sampling (AVS) is required to identify a lateralized or bilateral aldosterone source in primary aldosteronism. OBJECTIVES: Our objectives were to compare basal and post-ACTH selectivity ratio (SR) and lateralization ratio (LR) and to determine the prevalence of basal contralateral suppression and its effect on surgical outcome. PATIENTS AND INTERVENTION: Bilateral simultaneous adrenal vein samples were obtained before and after a 250-µg bolus of ACTH. Analyses were conducted on 171 technically successful AVS and on the subgroup of 66 operated patients with evaluable outcome data. RESULTS: ACTH increased selectivity on both sides from 66.7% in basal samples (SR ≥ 2) to 91.8% poststimulation (SR ≥ 5). A discordance of lateralization between basal (LR ≥ 2) and post-ACTH (LR ≥ 4) values was observed in 28% of cases, which were mostly lateralized cases basally that became bilateral post-ACTH. Basal CL suppression is present in only 30% using absolute ratio of aldosterone between the opposite (nondominant) adrenal vein and the peripheral vein AOPP/AP below 1.5 vs in 77% using aldosterone/cortisol ratio (A/C)OPP/(A/C)P below 1.5. The absence of CL suppression was associated with a lower rate of response to adrenalectomy in terms of clinical and biochemical parameters with difference in clinical cure (55% vs 13% P = .0003) and overall cure (35% vs 9%, P = .0084) using AOPP/AP, but not when using (A/C)OPP/(A/C)P. CONCLUSIONS: Stimulation with ACTH is useful to improve selectivity of AVS but can frequently modify interpretation of lateralization. Basal ratios are as important as post-ACTH ratios to set an indication of adrenalectomy. AOPP/AP is superior to (A/C)OPP/(A/C)P to assess contralateral suppression. Infrequent CL suppression reveals frequent occurrence of contralateral hyperplasia in lateralized cases and helps predict postoperative outcomes.

Genetic aspects of adrenocortical tumours and hyperplasias.

Adrenocortical tumours (ACT), which include adenomas, carcinomas and adrenal hyperplasia, may be associated with genetic syndromes, such as Li-Fraumeni syndrome, Beckwith-Wiedemann syndrome, multiple endocrine neoplasia type 1, familial adenomatous polyposis and Carney complex. Genetic defects have been found to be responsible for the disease in most of these syndromes, allowing genetic counselling to affected patients and family members. Here, we summarize the clinical criteria of these hereditary syndromes and briefly describe the genetic alterations related to them. In addition, we discuss the involvement of various genetic defects in the development of sporadic adrenocortical tumours.

Combined expression of BUB1B, DLGAP5, and PINK1 as predictors of poor outcome in adrenocortical tumors: validation in a Brazilian cohort of adult and pediatric patients.

BACKGROUND: A recent microarray study identified a set of genes whose combined expression patterns were predictive of poor outcome in a cohort of adult adrenocortical tumors (ACTs). The difference between the expression values measured by qRT-PCR of DLGAP5 and PINK1 genes was the best molecular predictor of recurrence and malignancy. Among the adrenocortical carcinomas, the combined expression of BUB1B and PINK1 genes was the most reliable predictor of overall survival. The prognostic and molecular heterogeneity of ACTs raises the need to study the applicability of these molecular markers in other cohorts. OBJECTIVE: To validate the combined expression of BUB1B, DLGAP5, and PINK1 as outcome predictor in ACTs from a Brazilian cohort of adult and pediatric patients. PATIENTS AND METHODS: BUB1B, DLGAP5, and PINK1 expression was assessed by quantitative PCR in 53 ACTs from 52 patients - 24 pediatric and 28 adults (one pediatric patient presented a bilateral asynchronous ACT). RESULTS: DLGAP5-PINK1 and BUB1B-PINK1 were strong predictors of disease-free survival and overall survival, respectively, among adult patients with ACT. In the pediatric cohort, these molecular predictors were only marginally associated with disease-free survival but not with overall survival. CONCLUSION: This study confirms the prognostic value of the combined expression of BUB1B, DLGAP5, and PINK1 genes in a Brazilian group of adult ACTs. Among pediatric ACTs, other molecular predictors of outcome are required.

Characterization of differential gene expression in adrenocortical tumors harboring beta-catenin (CTNNB1) mutations.

BACKGROUND: Mutations of ß-catenin gene (CTNNB1) are frequent in adrenocortical adenomas (AA) and adrenocortical carcinomas (ACC). However, the target genes of ß-catenin have not yet been identified in adrenocortical tumors. OBJECTIVE: Our objective was to identify genes deregulated in adrenocortical tumors harboring CTNNB1 genetic alterations and nuclear accumulation of ß-catenin. METHODS: Microarray analysis identified a dataset of genes that were differently expressed between AA with CTNNB1 mutations and wild-type (WT) tumors. Within this dataset, the expression profiles of five genes were validated by real time-PCR (RT-PCR) in a cohort of 34 adrenocortical tissues (six AA and one ACC with CTNNB1 mutations, 13 AA and four ACC with WT CTNNB1, and 10 normal adrenal glands) and two human ACC cell lines. We then studied the effects of suppressing ß-catenin transcriptional activity with the T-cell factor/ß-catenin inhibitors PKF115-584 and PNU74654 on gene expression in H295R and SW13 cells. RESULTS: RT-PCR analysis confirmed the overexpression of ISM1, RALBP1, and PDE2A and the down-regulation of PHYHIP in five of six AA harboring CTNNB1 mutations compared with WT AA (n = 13) and normal adrenal glands (n = 10). RALBP1 and PDE2A overexpression was also confirmed at the protein level by Western blotting analysis in mutated tumors. ENC1 was specifically overexpressed in three of three AA harboring CTNNB1 point mutations. mRNA expression and protein levels of RALBP1, PDE2A, and ENC1 were decreased in a dose-dependent manner in H295R cells after treatment with PKF115-584 or PNU74654. CONCLUSION: This study identified candidate genes deregulated in CTNNB1-mutated adrenocortical tumors that may lead to a better understanding of the role of the Wnt-ß-catenin pathway in adrenocortical tumorigenesis.

Glucose-dependent insulinotropic peptide receptor expression in the hippocampus and neocortex of mesial temporal lobe epilepsy patients and rats undergoing pilocarpine induced status epilepticus.

The glucose-dependent insulinotropic peptide receptor (GIPR) has been implicated with neuroplasticity and may be related to epilepsy. GIPR expression was analyzed by immunohistochemistry in the hippocampus (HIP) and neocortex (Cx) of rats undergoing pilocarpine induced status epilepticus (Pilo-SE), and in three young male patients with left mesial temporal lobe epilepsy related to hippocampal sclerosis (MTLE-HS) treated surgically. A combined GIPR immunohistochemistry and Fluoro-Jade staining was carried out to investigate the association between the GIPR expression and neuronal degeneration induced by Pilo-SE. GIPR was expressed in the cytoplasm of neurons from the HIP CA subfields, dentate gyrus (DG) and Cx of animals and human samples. The GIPR expression after the Pilo-SE induction increases significantly in the HIP after 1h and 5 days, but not after 12h or 50 days. In the Cx, the GIPR expression increases after 1h, 12h and 5 days, but not 50 days after the Pilo-SE. The expression of GIPR 12h after Pilo-SE was inversely proportional to the Fluoro-Jade staining intensity. In the human tissue, GIPR expression patterns were similar to those observed in chronic Pilo-SE animals. No Fluoro-Jade stained cells were observed in the human sample. GIPR is expressed in human HIP and Cx. There was a time and region dependent increase of GIPR expression in the HIP and Cx after Pilo-SE that was inversely associated to neuronal degeneration.

Role of the glucose-dependent insulinotropic polypeptide and its receptor in the central nervous system: therapeutic potential in neurological diseases.

Glucose-dependent insulinotropic polypeptide (GIP) is a 42-amino acid hormone, secreted from the enteroendocrine K cells, which has insulin-releasing and extra-pancreatic actions. GIP and its receptor present a widespread distribution in the mammalian brain where they have been implicated with synaptic plasticity, neurogenesis, neuroprotection and behavioral alterations. This review attempts to provide a comprehensive picture of the role of GIP in the central nervous system and to highlight recent findings from our group showing its potential involvement in neurological illnesses including epilepsies, Parkinson's disease and Alzheimer's disease.

Aberrant G-protein coupled receptor expression in relation to adrenocortical overfunction.

The aberrant adrenal expression and function of one or several G-protein coupled receptors can lead to cell proliferation and abnormal regulation of steroidogenesis in unilateral adenomas, carcinomas or in ACTH-independent macronodular adrenal hyperplasia (AIMAH). Excess cortisol secretion leading to either sub-clinical or overt Cushing's syndrome is the most prevalent phenotype reported to date. In a few patients, aberrant regulation of androgen excess has been reported. More recently, initial studies suggest that similar mechanisms are involved in the renin-independent regulation of aldosterone secretion in primary aldosteronism. In recent years, cases of familial AIMAH have been identified, and specific aberrant hormone receptors are functional in the adrenal of affected members. The identification of aberrant receptors can offer specific pharmacological approach to prevent disease progression and control abnormal steroidogenesis; alternatively, unilateral or bilateral adrenalectomy remains the treatment of choice.

Adrenal Cushing's syndrome due to bilateral macronodular adrenal hyperplasia: prediction of the efficacy of beta-blockade therapy and interest of unilateral adrenalectomy.

Bilateral adrenalectomy is the standard treatment for Cushing's syndrome (CS) related to ACTH-independent bilateral macronodular hyperplasia (AIMAH), although it imposes life-long adrenal insufficiency. This study reports a clinical case in order to discuss the clinical interest of pharmacological beta-blockade of illegitimate membrane receptors and unilateral adrenalectomy as alternatives to bilateral adrenalectomy for treatment of CS due to AIMAH. Evidence for cortisol stimulation by upright posture and insulin-induced hypoglycemia in a patient with CS related to AIMAH led us to try beta-blockers as a therapeutic test and then as a first line treatment. Thus, a 3-day beta-blocker test (320 mg/d propranolol) induced normalization of cortisol secretion, with return of hypercortisolism at the end of the test. A long term treatment with 320 mg/d propranolol allowed sustained normalization of cortisol secretion and progressive disappearance of Cushingoid features but after 8 months the patient complained of Raynaud's syndrome and fatigue. Lowering propranolol dosage or switching to atenolol was less efficient to reduce cortisol levels. Unilateral adrenalectomy was then performed as a second line treatment, leading to normalisation of the 24h urinary cortisol without adrenal insufficiency. Long term control of blood pressure and glycemia were observed during a 7-year follow-up without beta-blocker. In conclusion, a 3-day propranolol test may identify patients with AIMAH who can benefit from a long term beta-blocker treatment. In case of intolerance to beta-blocking agents, unilateral adrenalectomy may allow for long term control of Cushing's syndrome related to AIMAH without adrenal insufficiency.

Cellular and molecular abnormalities of a macronodular adrenal hyperplasia causing beta-blocker-sensitive Cushing's syndrome

Cushing's syndrome due to ACTH-independent macronodular adrenal hyperplasia (AIMAH) can be associated with abnormal responses of aberrantly expressed adrenocortical receptors. This study aimed to characterize in vitro the pathophysiology of hypercortisolism in a b-blocker-sensitive Cushing's syndrome due to AIMAH. Cortisol secretion profile under aberrant receptors stimulation revealed hyperresponsiveness to salbutamol (beta2-adrenoceptor agonist), cisapride (5-HT4 receptor agonist), and vasopressin in AIMAH cultured cells, but not in normal adrenocortical cells. By RT-PCR, AIMAH tissues revealed beta2-adrenoceptor overexpression rather than ectopical expression. MC2R expression was similar in both AIMAH and normal adrenocortical tissues. Curiously, cortisol levels of AIMAH cells under basal condition were 15-fold higher than those of control cells and were not responsive to ACTH. Analysis of culture medium from AIMAH cells could detect the presence of ACTH, which was immunohistochemically confirmed. Finally, the present study of AIMAH cells has identified: a) cortisol hyperresponsiveness to catecholamines, 5-HT4 and vasopressin in vitro, in agreement with clinical screening tests; b) abnormal expression of beta2-adrenoceptors in some areas of the hyperplastic adrenal tissue; c) autocrine loop of ACTH production. Altogether, the demonstration of aberrant responses to hormonal receptors and autocrine hormone production in the same tissue supports the assumption of multiple molecular alterations in adrenal macronodular hyperplasia.

A síndrome de Cushing secundária à hiperplasia adrenal macronodular independente de ACTH (AIMAH) pode estar associada com respostas anômalas a estímulos sobre receptores hormonais expressos de maneira aberrante no córtex adrenal. O objetivo deste trabalho foi caracterizar a fisiopatologia do hipercortisolismo in vitro na síndrome de Cushing responsiva a beta-bloqueadores decorrente de AIMAH. Em cultura de células, a secreção de cortisol apresentou resposta aumentada ao salbutamol (agonista beta2-adrenérgico), à cisaprida (agonista de receptor 5-HT4) e à vasopressina, na AIMAH mas não no córtex adrenal normal. O estudo de receptores aberrantes por RT-PCR demonstrou que o gene do receptor beta2-adrenérgico estava superexpresso (e não expresso ectopicamente) nos fragmentos da AIMAH quando comparado ao tecido normal. A expressão de MC2R foi semelhante em ambos. Curiosamente, o nível basal de secreção de cortisol pelas células da AIMAH foi 15 vezes superior às células normais, não havendo resposta das células AIMAH ao estímulo com ACTH. A análise do meio de cultura das células AIMAH revelou a presença de ACTH, que foi confirmada por estudo imuno-histoquímico. Em suma, este estudo demonstrou: a) aumento dos níveis de cortisol in vitro em resposta a catecolaminas, 5-HT4 e vasopressina, correspondendo aos resultados dos testes clínicos para pesquisa de receptores aberrantes; b) expressão anormal de receptores beta2-adrenérgicos em algumas áreas de hiperplasia; c) produção autócrina de ACTH. Estes resultados envolvendo ativação de receptores aberrantes e estímulo hormonal autócrino no mesmo tecido favorecem a hipótese da existência de alterações moleculares múltiplas na hiperplasia adrenal macronodular.

Detection of Torque teno virus in Epstein-Barr virus positive and negative lymph nodes of patients with Hodgkin lymphoma.

The age-specific incidence of Hodgkin lymphoma (HL) is bimodal with peaks occurring among young adults (15 - 34 years old) and people older than 45 years. Epstein-Barr virus (EBV) is associated with only one-third of HL cases. This study sought to determine if Torque teno virus (TTV) might be independently associated with HL. The presence of EBV was appraised by in situ hybridization and immunohistochemistry in lymph node biopsies from 46 patients (3 - 81 years old) with HL. TTV DNA was assessed by PCR amplification. EBV was detected in 22 (48%) patients. TTV DNA was detected in 24/46 (52%) patients, as well as in 12/20 (60%) control patients with lymphoid unspecific hyperplasia. TTV DNA was not significantly more frequent in EBV negative (54%) than in EBV positive (50%) nodes. However, it was observed that the group of young adults (15 - 34 years, n = 19) showed the lowest EBV frequency (21%) but the highest TTV occurrence (60%). This may suggest an involvement of TTV infection in the pathogenesis of HL in young adults. Further large population-based studies are required to confirm our findings.

Cellular and molecular abnormalities of a macronodular adrenal hyperplasia causing beta-blocker-sensitive Cushing's syndrome.

Cushing's syndrome due to ACTH-independent macronodular adrenal hyperplasia (AIMAH) can be associated with abnormal responses of aberrantly expressed adrenocortical receptors. This study aimed to characterize in vitro the pathophysiology of hypercortisolism in a beta-blocker-sensitive Cushing's syndrome due to AIMAH. Cortisol secretion profile under aberrant receptors stimulation revealed hyperresponsiveness to salbutamol (beta2-adrenoceptor agonist), cisapride (5-HT4 receptor agonist), and vasopressin in AIMAH cultured cells, but not in normal adrenocortical cells. By RT-PCR, AIMAH tissues revealed beta2-adrenoceptor overexpression rather than ectopical expression. MC2R expression was similar in both AIMAH and normal adrenocortical tissues. Curiously, cortisol levels of AIMAH cells under basal condition were 15-fold higher than those of control cells and were not responsive to ACTH. Analysis of culture medium from AIMAH cells could detect the presence of ACTH, which was immunohistochemically confirmed. Finally, the present study of AIMAH cells has identified: a) cortisol hyperresponsiveness to catecholamines, 5-HT4 and vasopressin in vitro, in agreement with clinical screening tests; b) abnormal expression of beta2-adrenoceptors in some areas of the hyperplastic adrenal tissue; c) autocrine loop of ACTH production. Altogether, the demonstration of aberrant responses to hormonal receptors and autocrine hormone production in the same tissue supports the assumption of multiple molecular alterations in adrenal macronodular hyperplasia.

The cytotoxic effect and the multidrug resistance reversing action of lignans from Phyllanthus amarus.

Multidrug resistance (MDR) constitutes the major obstacle to the successful treatment of cancer. In several cancer cells, MDR is thought to be mediated by the super-expression of P-glycoprotein (Pgp). Pgp extrudes drugs from the cells, therefore reducing their cytotoxicity, and its activity inhibition may reverse the MDR phenotype. The present study evaluated the possible cytotoxic effect and MDR reversing properties of the extract and compounds isolated from Phyllanthus amarus. To this purpose, two human leukaemia cell lines were employed: K-562 and its vincristine-resistant counterpart Lucena-1, a Pgp-overexpressing subline. We report here that Lucena-1 was significantly more resistant to the cytotoxicity of P. amarus derivatives: the hexane extract (HE, 100 microg/mL), the lignans-rich fraction (LRF, 100 microg/mL) and the lignans nirtetralin (NIRT, 43.2 microg/mL), niranthin (NIRA, 43 microg/mL) or phyllanthin (PHYLLA, 43 microg/mL) exerted cytotoxic effects on K-562 cells with 40.3, 66.0, 62.0, 61.0 or 24.1% of cell death, respectively. The cellular toxicity observed on Lucena-1 was 16.3, 40.4, 29.4, 30.2, or 24.8%, respectively. However, cell treatment with the lignan phyltetralin (PHYLT) up to 41.6 microg/mL had no cytotoxic action on either of the cell lines. P. amarus derivatives were also found to be effective in inhibiting Pgp activity as assessed by rhodamine accumulation in Lucena-1 cells, as were the classical Pgp inhibitors, cyclosporine A (160 nM), PSC-833 (2 microM) and verapamil (5 microM). The lignan NIRT produced the most potent inhibition (EC (50) = 29.4 microg/mL) followed by NIRA (44.3 microg/mL), LRF (49.1 microg/mL), PHYLT (99.4 microg/mL), PHYLLA and HE (> 100 microg/mL). Lucena-1 cells were more resistant to daunorubicin-induced cell death (LC (50) = 50 microM) than K562 cells (LC (50) = 4.95 microM). Of note, the P. amarus derivatives significantly potentiated 5 microM daunorubicin-induced cell death in Lucena-1 cells (P < 0.01) but not in K562 cells. After treatment only with P. amarus derivatives (100 microg/mL HE, 30 microg/mL LRF, 12.9 microg/mL NIRA, 43.2 microg/mL NIRT, 43 microg/mL PHYLLA or 41.6 microg/mL PHYLT), the Lucena-1 cellular viability was 83.7, 85.3, 101, 69.7, 75.6 or 88.7%, respectively, whereas the in the presence of daunorubincin, which was not cytotoxic PER SE, the cell viability decreased to 42.9, 42.2, 64.2, 35.4, 30.4 or 52.6%, respectively. Together, these results suggest a potential action of P. amarus derivatives as MDR reversing agents, mainly due to their ability to synergize with the action of conventional chemotherapeutics.

Ectopic expression of the gastric inhibitory polypeptide receptor gene is a sufficient genetic event to induce benign adrenocortical tumor in a xenotransplantation model.

Aberrant expression of ectopic G protein-coupled receptors (GPCRs) in adrenal cortex tissue has been observed in several cases of ACTH-independent macronodular adrenal hyperplasias and adenomas associated with Cushing's syndrome. Although there is clear clinical evidence for the implication of these ectopic receptors in abnormal regulation of cortisol production, whether this aberrant GPCR expression is the cause or the consequence of the development of an adrenal hyperplasia is still an open question. To answer it, we genetically engineered primary bovine adrenocortical cells to have them express the gastric inhibitory polypeptide receptor. After transplantation of these modified cells under the renal capsule of adrenalectomized immunodeficient mice, tissues formed had their functional and histological characteristics analyzed. We observed the formation of an enlarged and hyperproliferative adenomatous adrenocortical tissue that secreted cortisol in a gastric inhibitory polypeptide-dependent manner and induced a mild Cushing's syndrome with hyperglycemia. Moreover, we show that tumor development was ACTH independent. Thus, a single genetic event, inappropriate expression of a nonmutated GPCR gene, is sufficient to initiate the complete phenotypic alterations that ultimately lead to the formation of a benign adrenocortical tumor.