Implication of Pappalysins and Stanniocalcins in the Bioavailability of IGF-I in Children With Type 1 Diabetes Mellitus.

Context: Anomalies in the growth hormone (GH)/insulin-like growth factor (IGF) axis, are common in children with type 1 diabetes mellitus (T1DM), even in those reaching a normal or near-normal final height. However, concentrations of the IGF bioavailability regulatory factors (pappalysins [PAPP-As] and stanniocalcins [STCs]) have not been reported in children with T1DM. Objective: To determine serum concentrations of PAPP-As and STCs in children at diagnosis of T1DM and after insulin treatment and the correlation of these factors with other members of the GH/IGF axis, beta-cell insulin reserve, auxology, and nutritional status. Methods: A single-center prospective observational study including 47 patients (59.5% male), with T1DM onset at median age of 9.2 years (interquartile range: 6.3, 11.9) was performed. Blood and anthropometric data were collected at diagnosis and after 6 and 12 months of treatment. Results: At 6 and 12 months after T1DM diagnosis, there was improvement in the metabolic control (decrease in glycated hemoglobin [HbA1c] at 12 months -3.66 [95% CI: -4.81, -2.05], P = .001), as well as in body mass index SD and height SD (not statistically significant). STC2 increased (P < .001) and PAPP-A2 decreased (P < .001) at 6 and 12 months of treatment onset (P < .001), which was concurrent with increased total IGF-I and IGF-binding protein concentrations, with no significant modification in free IGF-I concentrations. HbA1c correlated with PAPP-A2 (r = +0.41; P < .05) and STC2 (r = -0.32; P < .05). Conclusion: Implementation of insulin treatment after T1DM onset modifies various components of the circulating IGF system, including PAPP-A2 and STC2. How these modifications modulate linear growth remains unknown.

NCoA3 upregulation in breast cancer­associated adipocytes elicits an inflammatory profile.

Nuclear receptor coactivator 3 (NCoA3) is a transcriptional coactivator of NF­κB and other factors, which is expressed at relatively low levels in normal cells and is amplified or overexpressed in several types of cancer, including breast tumors. NCoA3 levels have been shown to be decreased during adipogenesis; however, its role in tumor­surrounding adipose tissue (AT) remains unknown. Therefore, the present study assessed the modulation of NCoA3 in breast cancer­associated adipocytes and evaluated its association with the expression of inflammatory markers. 3T3­L1 adipocytes were stimulated with conditioned medium from human breast cancer cell lines and the expression levels of NCoA3 were evaluated by reverse transcription­quantitative (q)PCR. NF­κB activation was measured by immunofluorescence, and tumor necrosis factor and monocyte chemoattractant protein 1 levels were analyzed by qPCR and dot blot assays. The results obtained from the in vitro model were supported using mammary AT (MAT) from female mice, MAT adjacent to tumors from patients with breast cancer and bioinformatics analysis. The results revealed that adipocytes expressing high levels of NCoA3 were mainly associated with a pro­inflammatory profile. In 3T3­L1 adipocytes, NCoA3 downregulation or NF­κB inhibition reversed the expression of inflammatory molecules. In addition, MAT from patients with a worse prognosis exhibited high levels of this coactivator. Notably, adipocyte NCoA3 levels could be modulated by inflammatory signals from tumors. The modulation of NCoA3 levels in synergy with NF­κB activity in MAT in a tumor context could be factors required to establish breast cancer­associated inflammation. As adipocytes are involved in the development and progression of breast cancer, this signaling network deserves to be further investigated to improve future tumor treatments.

Endocrine Sequelae in 157 Pediatric Survivors of Hematopoietic Stem Cell Transplantation (HSCT).

Context: Successful rates of hematopoietic stem cell transplantation (HSCT) face paralleled escalation of late endocrine and metabolic effects. Objective: This work aimed to characterize these sequelae distinguishing between the underlying pathologies and treatments received. Methods: A retrospective descriptive study was conducted in 157 children post-HSCT (hematopoietic pathology [N = 106], solid tumors [N = 40], and rare entities [N = 11]) followed at a single endocrine department between 2009 and 2019. Regression analysis was used to ascertain association. Results: Of all patients, 58.7% presented with at least one endocrine abnormality. Endocrinopathies post HSCT were most frequently developed in lymphoblastic leukemia (60.5% of them), whereas myeloid leukemias had the fewest. A total of 64% of patients presented with primary hypogonadism, 52% short stature, and 20% obesity. Endocrinopathy was associated with older age at HSCT (9.78 years [6.25-12.25] vs 6.78 years [4.06-9.75]) (P < .005), pubertal Tanner stage V (P < .001), chronic graft-vs-host disease (GVHD) (P = .022), and direct gonadal therapy (P = .026). The incidence of endocrinopathies was higher in girls (15% more common; P < .02) and in patients who received radiotherapy (18% higher), steroids (17.4% increase), allogenic HSCT (7% higher), thymoglobulin, or cyclophosphamide. Those on busulfan presented with a 27.5% higher rate of primary hypogonadism (P = .003). Conclusion: More than half of children surviving HSCT will develop endocrinopathies. Strikingly, obesity has risen to the third most frequent endocrine disruption, mainly due to steroids, and partly adhering to the general population tendency. Lymphoblastic leukemia was the condition with a higher rate of endocrine abnormalities. Female sex, older age at HSCT, pubertal stage, allogenic transplant, radiotherapy, alkylating drugs, and GVHD pose risk factors for endocrine disturbances.

Pappalysins and Stanniocalcins and Their Relationship With the Peripheral IGF Axis in Newborns and During Development.

CONTEXT: Pappalysins (PAPP-A, PAPP-A2) modulate body growth by increasing insulin-like growth factor I (IGF-I) bioavailability through cleavage of insulin-like growth factor binding proteins (IGFBPs) and are inhibited by stanniocalcins (STC1, STC2). Normative data on these novel factors, as well as on free IGF-I and uncleaved fractions of IGFBPs, are not well established. OBJECTIVE: This work aimed to determine serum concentrations of PAPP-A, PAPP-A2, STC1, and STC2 in relationship with other growth hormone (GH)-IGF axis parameters during development. METHODS: Full-term newborns (150; gestational age: 39.30 ±â€…1.10 weeks), 40 preterm newborns (30.87 ±â€…3.35 weeks), and 1071 healthy individuals (aged 1-30 years) were included in the study and divided according to their Tanner stages (males and females): I:163 males, 154 females; II:100 males, 75 females; III:83 males, 96 females; IV: 77 males, 86 females; and V:109 males,128 females. RESULTS: Serum concentrations of PAPP-A, PAPP-A2, STC1, STC2, IGFBP-2, total IGFBP-4, and total IGFBP-5 were elevated at birth and declined throughout childhood. In postnatal life, PAPP-A2 concentrations decreased progressively in concomitance with the free/total IGF-I ratio; however, stanniocalcin concentrations remained stable. PAPP-A2 concentrations positively correlated with the free/total IGF-I ratio (r = +0.28; P < .001) and negatively with the intact/total IGFBP-3 ratio (r = -0.23; P < .001). PAPP-A concentrations inversely correlated with intact/total IGFBP-4 ratio (r = -0.21; P < .001), with PAPP-A concentrations being lower in females at all ages. Association studies indicate the importance of stanniocalcins and pappalysins in the control of this axis in an age-specific manner. CONCLUSION: This study provides reference values of pappalysins and stanniocalcins, which modulate IGF-I activity by changing the concentrations of cleaved and uncleaved IGFBPs.

When is it best to discontinue diazoxide in children with persistent hyperinsulinaemic hypoglycaemia and negative genetics for KATP channel gene variants?

Diazoxide is the first-line treatment in children with hyperinsulinaemic hypoglycaemia (HH); however, limited information is available on the duration of diazoxide treatment in children who require over 2 years of it. Hence, we retrospectively reviewed the clinical and biochemical aspects, as well as the duration of therapy and neurodevelopmental assessment, in genetically uncharacterised diazoxide-responsive HH patients admitted to a tertiary hospital over the last 16 years, who had successfully discontinued diazoxide and remained euglycaemic. To exclude transient HH forms, only patients that required diazoxide for over 2 years were studied. We identified a total of 17 patients (70% males), in whom HH was diagnosed between 1 day and 18 months of age, and 88% were born at term with a median birth weight of 3.79 kg. All children responded to diazoxide at a median dose of 11.5 mg/kg/day, and it was stopped at a median age of 8.5 years, with a median duration of therapy of 7.25 years. The cases that required diazoxide the longest manifested no specific biochemical or clinical characteristics. Fasting tests performed after diazoxide discontinuation showed no longer requirement of diazoxide in all the cases. A total of 64.7% of the children showed mild to moderate developmental delay. Therefore, it seems that long-term resolution of HH in children with negative genetics for KATP channel genes who required diazoxide for over 2 years will ensue, and thus regular evaluation is crucial. The possible molecular mechanisms involved are unclear.

Syndromic Forms of Hyperinsulinaemic Hypoglycaemia-A 15-year follow-up Study.

OBJECTIVE: Hyperinsulinaemic hypoglycaemia (HH) is one of the commonest causes of hypoglycaemia in children. The molecular basis includes defects in pathways that regulate insulin release. Syndromic conditions like Beckwith-Wiedemann (BWS), Kabuki (KS) and Turner (TS) are known to be associated with a higher risk for HH. This systematic review of children with HH referred to a tertiary centre aims at estimating the frequency of a syndromic/multisystem condition to help address stratification of genetic analysis in infants with HH. METHODS: We performed a retrospective study of 69 patients with syndromic features and hypoglycaemia in a specialist centre from 2004 to 2018. RESULTS: Biochemical investigations confirmed HH in all the cases and several genetic diagnoses were established. Responsiveness to medications and the final outcome following medical treatment or surgery were studied. CONCLUSIONS: This study highlights the association of HH with a wide spectrum of syndromic diagnoses and that children with features suggestive of HH-associated syndromes should be monitored for hypoglycaemia. If hypoglycaemia is documented, they should also be screened for possible HH. Our data indicate that most syndromic forms of HH are diazoxide-responsive and that HH resolves over time; however, a significant percentage continues to require medications years after the onset of the disease. Early diagnosis of hyperinsulinism and initiation of treatment is important for preventing hypoglycaemic brain injury and intellectual disability.

Rasmussen's encephalitis and central precocious puberty. Neuroendocrinological characterization of three cases.

PURPOSE: Rasmussen's encephalitis (RE) is a chronic neurological disorder characterized by inflammation of the cerebral cortex, mainly unilateral, that leads to drug-resistant epilepsy and progressive neurological impairment. Central Precocious Puberty (CPP) is uncommon, albeit increased in frequency in patients with neurological conditions and the physiopathological bases of these associations remains unclear in most cases. Epilepsy has been proposed to play a role, as well as the accumulation of substances produced as a result of metabolism or tissue degeneration in some neurodegenerative diseases. However, CPP has not been previously described in patients with RE. METHODS: From a series of patients affected by RE followed-up at a referral center, an in-depth review of the characteristics of those who developed CCP was carried out. RESULTS: Three cases were identified, representing a relative frequency of 21.4 % for CPP. They were girls, of Caucasian ethnicity, without family history of CPP or any image-identified abnormalities in the hypothalamic area. In two cases CPP manifested immediately before the onset of the epilepsy (prior to the diagnosis of RE) and in the other, after epilepsy onset but coinciding with a worsening of the seizures. A GnRH test with pubertal response confirmed CPP in the three cases. CONCLUSION: The high proportion of CPP in patients affected by RE suggested a plausible relationship between these two entities. Various factors involved, including neuroinflammation, are hypothesized in the present study. However, further studies are needed to elucidate the pathophysiological bases, which could provide insight in the understanding of both entities.

COVID-19 in Children and Adolescents with Endocrine Conditions.

The rapid spread of coronavirus disease (COVID-19) worldwide justifies global effort to combat the disease but also the need to review effective preventive strategies and medical management for potentially high-risk populations during the pandemic. Data regarding the COVID-19 manifestations in adults with underlying endocrine conditions, especially diabetes mellitus, are increasingly emerging. Albeit children and adolescents are considered to be affected in a milder manner, paucity of information regarding COVID-19 in children who suffer from endocrinopathies is available. The present review comprehensively collects recommendations issued by various health organizations and endocrine associations for the management of pediatric endocrine conditions during the pandemic. Adhering to the specific "sick day management rules" and undelayed seeking for medical advice are only needed in most of the cases, as the vast majority of children with endocrine disorders do not represent a high-risk population for contamination or severe presentation of COVID-19. Psychological implications in these children and adolescents are also considered.

Octreotide-related exocrine pancreatic insufficiency (EPI) in congenital hyperinsulinism.

Background Congenital hyperinsulinism (CH) is the most frequent cause of persistent hypoglycemia in the newborn. Octreotide, a long-acting somatostatin receptor analog (SSRA), is a second line treatment for diazoxide unresponsive CH patients. Although it has been found to be a safe and effective treatment, long-term benefits and side effects, have not been thoroughly evaluated. Case presentation Some authors have indicated that exocrine pancreatic insufficiency (EPI) is a common but under-recognized adverse reaction in adults treated with octreotide. However, no pediatric patient with SSRA-induced EPI has been reported to date. Here we report a case of an infant with diazoxide unresponsive, diffuse CH, caused by a heterozygous pathogenic paternally inherited mutation in the ABCC8 gene (NM_000352.4:c.357del), that developed exocrine pancreatic insufficiency and secondary vitamin K deficiency associated to chronic octreotide therapy. Conclusions We point out the atypical clinical onset with a cutaneous hemorrhagic syndrome, emphasizing the clinical relevance of this potential side effect.

Primary Dwarfism, Microcephaly, and Chorioretinopathy due to a PLK4 Mutation in Two Siblings.

INTRODUCTION: Primary autosomal recessive microcephalies (MCPHs) are characterized by primary dwarfism with MCPH and may present delayed psychomotor development and visual impairment. Biallelic loss of function variants in the PLK4 gene, which encodes the polo-like kinase 4 protein involved in centriole biogenesis, has been recently identified in several patients with MCPH and various ethnic backgrounds. CASE PRESENTATION: Here, we describe 2 siblings of different sex from Equatorial Guinea harboring a homozygous frameshift mutation in PLK4 (c.1299_1303del, p.Phe433Leufs*6). A Seckel syndrome spectrum phenotype was present in both siblings, with short stature, severe MCPH, reduced brain volume, and distinctive facial features. They also presented severe intellectual disability, lissencephaly/pachygyria, subependymal heterotopia, and ophthalmological impairment. One of them suffered from deafness, and scoliosis was observed in the other. DISCUSSION/CONCLUSION: Biallelic variants in PLK4 lead to a syndrome where severe short stature, MCPH, and cognitive impairment are constant features. However, ocular, skeletal, and other neurological manifestations can vary upon the same genetic basis.

Modelo demostrativo de identificación precoz y atención continua de pacientes con cáncer y necesidad paliativas / Demonstrative model for early identification and continuous care of cancer patients with palliative needs

Los cuidados paliativos (CP) se incorporaron en la salud pública de muchos países con gran variabilidad e inequidad. Argentina posee una incidencia de cáncer media-alta y el Programa Nacional de Cuidados Paliativos no identifica la población diana. El instrumento NECPAL CCOMS-ICO© identifica enfermos con necesidades paliativas. Combina una pregunta (¿Le sorprendería que su paciente falleciera en el próximo año?) con indicadores específicos. El objetivo fue identificar precozmente y mejorar la asistencia integral de pacientes con cáncer y necesidades paliativas. Se reporta la implementación de una intervención sanitaria (Programa Modelo de Atención Paliativa). MÉTODOS: Se incluyó a todos los pacientes oncológicos del hospital universitario (julio de 2014- julio de 2016). Se entrevistó a sus 10 médicos en 69 sesiones individuales con el NECPAL. Se diseñó un programa demostrativo en 4 etapas. RESULTADOS: Hubo 317 pacientes, 57% con necesidades paliativas (NECPAL+). Como resultado de la implementación, el 94% (n=172) de 183 pacientes NECPAL+ fueron derivados a CP (frente a 28% antes del programa); media de seguimiento de 7,4 meses y 183 fallecieron (28 en domicilio). Se superaron estándares de calidad de estructura, proceso y resultado. DISCUSIÓN: Por primera vez en Argentina, esta intervención sanitaria incluyó a casi la totalidad de pacientes con cáncer y necesidades paliativas tempranas en un programa de asistencia continua hasta su fallecimiento en el hospital o domicilio.

LZTR1: Genotype Expansion in Noonan Syndrome.

BACKGROUND: LZTR1 participates in RAS protein degradation, hence limiting the RAS/MAPK cascade. Pathogenic mutations in LZTR1 (MIM:600574) have been described in a few patients with Noonan syndrome (NS). Three patients with LZTR1 mutations of different genetic transmission and NS phenotype are herein characterized. CLINICAL CASES: Case 1 is a 5-year-old boy with NS phenotype. Sanger sequencing of PTPN11 and SOS1 identified no mutations. Whole exome sequencing (WES) detected a heterozygous missense mutation in LZTR1:c.742G>A (p.Gly248Arg) (exon 8, Kelch 4 functional domain). Bioinformatic algorithms predict a deleterious effect of this variant, previously described to cause NS. Case 2 is a 4-year-old boy with NS phenotype. Direct sequencing of 8 genes associated with NS identified no mutations. WES localized a homozygous missense mutation in LZTR1:c.2074T>C (p.Phe692Leu, exon 18). This mutation has not been reported before and is predicted to have a deleterious effect on the protein. Case 3 is an 8-year-old boy who shares NS phenotype with his mother. A multigene panel for RASopathies showed a heterozygous missense variant in LZTR1:c.730T>C (p.Ser244Pro) (exon 8; Kelch 4 functional domain) that was maternally inherited. This variant has not been previously described; however, in silico predictors classify it as deleterious. Familial segregation suggests its pathogenicity. CONCLUSIONS: The molecular approach for syndromic phenotypes associated with various genes should involve complete/updated panels or WES rather than gene-by-gene sequencing. RASopathy genetic panels should incorporate LZTR1. Patients with pathogenic mutations in LZTR1 exhibit a characteristic NS gestalt but variable cardiac, height, and neurodevelopment expressions, with recessive inheritance possibly associating with a more severe phenotype.

Partial diazoxide responsiveness in a neonate with hyperinsulinism due to homozygous ABCC8 mutation.

We report a case of partial diazoxide responsiveness in a child with severe congenital hyperinsulinaemic hypoglycaemia (CHI) due to a homozygous ABCC8 mutation. A term baby, with birth weight 3.8 kg, born to consanguineous parents presented on day 1 of life with hypoglycaemia. Hypoglycaemia screen confirmed CHI. Diazoxide was commenced on day 7 due to ongoing elevated glucose requirements (15 mg/kg/min), but despite escalation to a maximum dose (15 mg/kg/day), intravenous (i.v.) glucose requirement remained high (13 mg/kg/min). Genetic testing demonstrated a homozygous ABCC8 splicing mutation (c.2041-1G>C), consistent with a diffuse form of CHI. Diazoxide treatment was therefore stopped and subcutaneous (s.c.) octreotide infusion commenced. Despite this, s.c. glucagon and i.v. glucose were required to prevent hypoglycaemia. A trial of sirolimus and near-total pancreatectomy were considered, however due to the significant morbidity potentially associated with these, a further trial of diazoxide was commenced at 1.5 months of age. At a dose of 10 mg/kg/day of diazoxide and 40 µg/kg/day of octreotide, both i.v. glucose and s.c. glucagon were stopped as normoglycaemia was achieved. CHI due to homozygous ABCC8 mutation poses management difficulties if the somatostatin analogue octreotide is insufficient to prevent hypoglycaemia. Diazoxide unresponsiveness is often thought to be a hallmark of recessively inherited ABCC8 mutations. This patient was initially thought to be non-responsive, but this case highlights that a further trial of diazoxide is warranted, where other available treatments are associated with significant risk of morbidity. Learning points: Homozygous ABCC8 mutations are commonly thought to cause diazoxide non-responsive hyperinsulinaemic hypoglycaemia. This case highlights that partial diazoxide responsiveness in homozygous ABCC8 mutations may be present. Trial of diazoxide treatment in combination with octreotide is warranted prior to considering alternative treatments, such as sirolimus or near-total pancreatectomy, which are associated with more significant side effects.

The Use of a Long-Acting Somatostatin Analogue (Lanreotide) in Three Children with Focal Forms of Congenital Hyperinsulinaemic Hypoglycaemia.

BACKGROUND: A long-acting somatostatin analogue (lanreotide) is used in the management of a diazoxide-unresponsive diffuse form of congenital hyperinsulinism (CHI). However, no reports of its use in patients with the focal form of CHI exist. Case 1: A 1-month-old boy diagnosed with diazoxide-unresponsive CHI due to a paternal heterozygous ABCC8 gene mutation showed partial response to octreotide. 18F-DOPA-PET/CT scan revealed a focal lesion in the pancreatic head. Surgical removal of the lesion was unsuccessful. He was switched to monthly lanreotide treatment at the age of 11 months, which stabilised his blood glucose over a 12-month period. Case 2: A 1-month-old boy with diazoxide-unresponsive CHI due to a paternal heterozygous KCNJ11 gene mutation was partially responsive to octreotide. 18F-DOPA-PET/CT scan confirmed a focal pancreatic head lesion. Over 6 months, he underwent 3 lesionectomies and afterwards responded to octreotide. At the age of 9 months, treatment was switched to monthly lanreotide. Currently, he is aged 3, with stable glycaemia, and improved fasting tolerance. Case 3: A 3-week-old girl with a paternal heterozygous ABCC8 gene mutation was unresponsive to diazoxide. 18F-DOPA-PET/CT scan confirmed a focal pancreatic head lesion. She responded to octreotide, and her parents preferred to avoid pancreatic surgery. At the age of 20 months, treatment was switched to monthly lanreotide, resulting in euglycaemia over the last 7 months. CONCLUSION: CHI patients with focal pancreatic head lesions are challenging, especially if not surgically amenable. Conservative treatment is preferable, and lanreotide might be an option. The therapeutic impact of lanreotide treatment in patients with the focal forms of CHI should be confirmed in prospective studies with close monitoring of the side effects.

Post-Prandial Hyperinsulinaemic Hypoglycaemia after Oesophageal Surgery in Children.

INTRODUCTION: Post-prandial hyperinsulinaemic hypoglycaemia (PPHH) is a recognized complication of various gastric surgeries in children, but rarely reported after oesophageal atresia repair. We report 2 children diagnosed with PPHH after oesophageal surgery and the challenges of their management. Case 1: A 2-year-old boy diagnosed with oesophageal atresia at birth was surgically repaired requiring 6 oesophageal dilatations in the first year of life. At 11 months of age, he manifested hypoglycaemic seizures and investigations confirmed PPHH. Acarbose and diazoxide trials failed. He was managed with 17-h continuous gastrostomy feeds. Currently, he is 28 months old with euglycaemia on daytime bolus gastrostomy feeds and overnight 12-h continuous gastrostomy feeds. Case 2: A 6-month-old girl diagnosed with Wolf-Hirschhorn syndrome and tracheo-oesophageal fistula was surgically repaired, requiring monthly oesophageal dilatations. At 5 months of age, she was reported to have hypoglycaemia and PPHH was confirmed. She responded to diazoxide and continuous nasogastric tube feeds, but developed pulmonary hypertension pos-sibly diazoxide-induced. Subsequently, diazoxide was stopped and normoglycaemia was secured via 20-h continuous gastrostomy feeds. CONCLUSION: PPHH may be an underdiagnosed complication in children undergoing surgery for oesophageal atresia. These children must be monitored closely for symptoms of hypoglycaemia and if there are concerns must be screened for possible PPHH. Our cases demonstrate that continuous feeding regimens might be the only therapeutic option, until PPHH gradually lessens in intensity over time.

A novel GLI2 mutation responsible for congenital hypopituitarism and polymalformation syndrome.

OBJECTIVE: We report a novel GLI2 frameshift mutation and describe the phenotypic spectrum of mutations within this gene. PATIENTS AND METHODS: A male with congenital hypopituitarism and polymalformation syndrome was clinically, biochemically and neuroradiologically characterized. Genetic analysis for congenital hypopituitarism was performed using a targeted NGS custom gene panel. RESULTS: A heterozygous frameshift mutation, NM_005270.4:c.2125del, p.(Leu709Trpfs*15), was identified in GLI2 exon 12. This mutation has not been previously reported and confirms the diagnosis of Culler-Jones syndrome (MIM #615849). CONCLUSION: GLI2 mutations should be suspected in the presence of congenital hypopitutarism, characteristic facial abnormalities and polydactyly.

RAC3 influences the chemoresistance of colon cancer cells through autophagy and apoptosis inhibition.

BACKGROUND: RAC3 coactivator overexpression has been implicated in tumorigenesis, contributing to inhibition of apoptosis and autophagy. Both mechanisms are involved in resistance to treatment with chemotherapeutic agents. The aim of this study was to investigate its role in chemoresistance of colorectal cancer. METHODS: The sensitivity to 5-fluorouracil and oxaliplatin in colon cancer cells HT-29, HCT 116 and Lovo cell lines, expressing high or low natural levels of RAC3, was investigated using viability assays. RESULTS: In HCT 116 cells, we found that although 5-fluorouracil was a poor inducer of apoptosis, autophagy was strongly induced, while oxaliplatin has shown a similar ability to induce both of them. However, in HCT 116 cells expressing a short hairpin RNA for RAC3, we found an increased sensitivity to both drugs if it is compared with control cells. 5-Fluorouracil and oxaliplatin treatment lead to an enhanced caspase 3-dependent apoptosis and produce an increase of autophagy. In addition, both process have shown to be trigged faster than in control cells, starting earlier after stimulation. CONCLUSIONS: Our results suggest that RAC3 expression levels influence the sensitivity to chemotherapeutic drugs. Therefore, the knowledge of RAC3 expression levels in tumoral samples could be an important contribution to design new improved therapeutic strategies in the future.

Sirolimus precipitating diabetes mellitus in a patient with congenital hyperinsulinaemic hypoglycaemia due to autosomal dominant ABCC8 mutation.

BACKGROUND: Sirolimus (mTOR inhibitor) is proven to be effective in children with congenital hyperinsulinism (CHI). Studies in animals suggest that sirolimus may have diabetogenic actions. However, its role in precipitating diabetes mellitus (DM) in children with CHI has not been reported. CASE PRESENTATION: A 16-year-old female with CHI due to a dominant ABCC8 gene mutation was switched from diazoxide therapy to sirolimus, due to the hypertrichosis side effect of diazoxide. She developed facial cellulitis that was treated with clarithromycin and a month later, once the infection was resolved, she was found to have persistent hyperglycaemia, and was diagnosed with DM. She was unresponsive to oral sulfonylurea therapy and is currently managed with metformin. Her mother, who had the same ABCC8 mutation, developed DM at her 30s. CONCLUSIONS: Patients with dominant ABCC8 gene mutations are prone to DM in adulthood, but Sirolimus therapy might increase the risk of developing diabetes at an early age, as this case illustrates.

Assessment of Nifedipine Therapy in Hyperinsulinemic Hypoglycemia due to Mutations in the ABCC8 Gene.

CONTEXT: Previous case reports have documented the effectiveness of l-type calcium channel blockers (such as nifedipine and verapamil) for treating different forms of hyperinsulinemic hypoglycemia (HH). OBJECTIVE: To systematically assess the glycemic response to nifedipine therapy in 11 patients with HH due to mutations in the ABCC8 gene. DESIGN: Dose escalation of nifedipine therapy. SETTINGS AND PATIENTS: Eleven children who were inpatients at a tertiary hospital and had diazoxide unresponsive HH due to mutations in the ABCC8 gene. INTERVENTION(S): Nifedipine was administered orally at an escalating dose up to a maximum of 2.5 mg/kg/d. MAIN OUTCOME MEASURES: Improvement in glycemic control, avoidance of hypoglycemic episodes, reduction of intravenous glucose infusion, and reduction in the requirements of other medical therapies. RESULTS: The median age of the patients was 0.44 years (range 0.14 to 3.77). The ABCC8 gene mutations were homozygous in 3 cases, paternally inherited heterozygous in 4, and compound heterozygous in 4. 18F-DOPA PET/CT scan demonstrated a focal lesion in 2 cases and the rest were diffuse HH disease. One subject had nifedipine as monotherapy, whereas the rest had it in combination with octreotide/glucagon/diazoxide or cornstarch. After a median of 6.5 (3 to 23) days of maximal (2.5 mg/kg/d) dose of nifedipine therapy, none of the patients showed any improvement in glycemic control and patients continued to have hypoglycemic episodes. CONCLUSIONS: HH due to mutations in the ABCC8 gene does not respond to nifedipine therapy. Mutations in the KATP channel genes might render the l-type calcium channel ineffective to therapy with nifedipine.