Patient empowerment improves follow-up data collection after fetal surgery for spina bifida: institutional audit

OBJECTIVES

To define and grade fetal and maternal adverse events following fetal surgery for spina bifida and to report on the impact of engaging patients in collecting follow-up data.

METHODS

This prospective single-center audit included 100 consecutive patients undergoing fetal surgery for spina bifida between January 2012 and December 2021. In our setting, patients return to their referring unit for further pregnancy care and delivery. On discharge, referring hospitals were requested to return outcome data. For this audit, we prompted patients and referring hospitals to provide data in cases of missing outcomes. Outcomes were categorized as missing, returned spontaneously or returned following additional request, by the patient and/or referring center. Postoperative maternal and fetal complications until delivery were defined and graded according to Maternal and Fetal Adverse Event Terminology (MFAET) and the Clavien-Dindo classification.

RESULTS

There were no maternal deaths, but severe maternal complications occurred in seven women (anemia in pregnancy, postpartum hemorrhage, pulmonary edema, lung atelectasis, urinary tract obstruction and placental abruption). No cases of uterine rupture were reported. Perinatal death occurred in 3% of fetuses and other severe fetal complications in 15% (perioperative fetal bradycardia/cardiac dysfunction, fistula-related oligohydramnios, chorioamnionitis and preterm prelabor rupture of membranes (PPROM) before 32 weeks). PPROM occurred in 42% of patients and, overall, delivery took place at a median gestational age of 35.3 weeks (interquartile range, 34.0-36.6 weeks). Information provided following additional request, from both centers and patients but mainly from the latter, reduced missing data by 21% for gestational age at delivery, 56% for uterine-scar status at birth and 67% for shunt insertion at 12 months. Compared with the generic Clavien-Dindo classification, the MFAET system ranked complications in a more clinically relevant way.

CONCLUSIONS

The nature and rate of severe complications following fetal surgery for spina bifida were similar to those reported in other large series. Spontaneous return of outcome data by referring centers was low, yet patient empowerment improved data collection. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Lipid droplet degradation by autophagy connects mitochondria metabolism to Prox1-driven expression of lymphatic genes and lymphangiogenesis

Autophagy has vasculoprotective roles, but whether and how it regulates lymphatic endothelial cells (LEC) homeostasis and lymphangiogenesis is unknown. Here, we show that genetic deficiency of autophagy in LEC impairs responses to VEGF-C and injury-driven corneal lymphangiogenesis. Autophagy loss in LEC compromises the expression of main effectors of LEC identity, like VEGFR3, affects mitochondrial dynamics and causes an accumulation of lipid droplets (LDs) in vitro and in vivo. When lipophagy is impaired, mitochondrial ATP production, fatty acid oxidation, acetyl-CoA/CoA ratio and expression of lymphangiogenic PROX1 target genes are dwindled. Enforcing mitochondria fusion by silencing dynamin-related-protein 1 (DRP1) in autophagy-deficient LEC fails to restore LDs turnover and lymphatic gene expression, whereas supplementing the fatty acid precursor acetate rescues VEGFR3 levels and signaling, and lymphangiogenesis in LEC-Atg5^-/- mice. Our findings reveal that lipophagy in LEC by supporting FAO, preserves a mitochondrial-PROX1 gene expression circuit that safeguards LEC responsiveness to lymphangiogenic mediators and lymphangiogenesis.

BNIP3 promotes HIF-1α-driven melanoma growth by curbing intracellular iron homeostasis

BNIP3 is a mitophagy receptor with context-dependent roles in cancer, but whether and how it modulates melanoma growth in vivo remains unknown. Here, we found that elevated BNIP3 levels correlated with poorer melanoma patient's survival and depletion of BNIP3 in B16-F10 melanoma cells compromised tumor growth in vivo. BNIP3 depletion halted mitophagy and enforced a PHD2-mediated downregulation of HIF-1α and its glycolytic program both in vitro and in vivo. Mechanistically, we found that BNIP3-deprived melanoma cells displayed increased intracellular iron levels caused by heightened NCOA4-mediated ferritinophagy, which fostered PHD2-mediated HIF-1α destabilization. These effects were not phenocopied by ATG5 or NIX silencing. Restoring HIF-1α levels in BNIP3-depleted melanoma cells rescued their metabolic phenotype and tumor growth in vivo, but did not affect NCOA4 turnover, underscoring that these BNIP3 effects are not secondary to HIF-1α. These results unravel an unexpected role of BNIP3 as upstream regulator of the pro-tumorigenic HIF-1α glycolytic program in melanoma cells.

BNIP3 contributes to the glutamine-driven aggressive behavior of melanoma cells

Aerobic glycolysis ('Warburg effect') is used by cancer cells to fuel tumor growth. Interestingly, metastatic melanoma cells rely on glutaminolysis rather than aerobic glycolysis for their bioenergetic needs through the tricarboxylic acid (TCA) cycle. Here, we compared the effects of glucose or glutamine on melanoma cell proliferation, migration and oxidative phosphorylation in vitro. We found that glutamine-driven melanoma cell's aggressive traits positively correlated with increased expression of HIF1α and its pro-autophagic target BNIP3. BNIP3 silencing reduced glutamine-mediated effects on melanoma cell growth, migration and bioenergetics. Hence, BNIP3 is a vital component of the mitochondria quality control required for glutamine-driven melanoma aggressiveness.

Lysosomal Pathways and Autophagy Distinctively Control Endothelial Cell Behavior to Affect Tumor Vasculature

Cancer cell-stromal cell crosstalk is orchestrated by a plethora of ligand-receptor interactions generating a tumor microenvironment (TME) which favors tumor growth. The high pro-angiogenic nature of the TME perpetuates the chaotic network of structurally immature, low pericyte-covered vessels characteristic of the tumor vasculature. We previously demonstrated that chloroquine (CQ) -a lysosomotropic agent used as first-generation autophagy blocker in clinical trials- induced tumor vessel normalization and reduced tumor hypoxia. CQ improved both vessel structure and maturation, whereas the conditional knockout of the crucial autophagy gene Atg5 in endothelial cells (ECs) did not, thus highlighting a potential differential role for EC-associated autophagy and the lysosomes in pathological tumor angiogenesis. However, how CQ or ATG5-deficiency in ECs affect angiogenic signals regulating EC-pericyte interface and therefore vessel maturation, remains unknown. Here, we show that in ECs CQ constrained VEGF-A-mediated VEGF receptor (VEGFR)2 phosphorylation, a driver of angiogenic signaling. In the presence of CQ we observed increased expression of the decoy receptor VEGFR1 and of a lower molecular weight form of VEGFR2, suggesting receptor cleavage. Consequently, VEGF-A-driven EC spheroid sprouting was reduced by CQ treatment. Furthermore, CQ significantly affected the transcription and secretion of platelet-derived growth factor (PDGF)-AB/BB (upregulated) and Endothelin-1 (EDN1, downregulated), both modulators of perivascular cell (PC) behavior. In contrast, silencing of ATG5 in ECs had no effect on VEGFR2 to VEGFR1 ratio nor on PDGFB and EDN1 expression. Accordingly, mice harboring B16F10 melanoma tumors treated with CQ, displayed both an increased number of αSMA⁺ PCs covering tumor vessels and co-expressed PDGF receptor-β, enabling PDGF ligand dependent recruitment. Moreover, upon CQ treatment the tumoral expression of angiopoietin-1 (Angpt1), which retains mural cells, and induces vessel stabilization by binding to the EC-localized cognate receptor (TIE2), was increased thus supporting the vessel normalization function of CQ. These features associated with improved tumor vasculature were not phenocopied by the specific deletion of Atg5 in ECs. In conclusion, this study further unravels endothelial cell autonomous and non-autonomous mechanisms by which CQ “normalizes” the intercellular communication in the tumor vasculature independent of autophagy.

The Streptokinase Reactivity Test. I. Standardization

1. An attempt was made to standardize a method which determines the reactivity of a given blood sample with streptokinase (SKRT).

2. The nature of the thrombin and streptokinase used can greatly influence the test.

3. The 20 minutes value is less influenced by a number of parameters than other points on the streptokinase versus lysis time plot.

Enhancing the Fibrinolytic Activity in Human Blood by Occlusion of Blood Vessels

The lytic activity was measured in blood obtained from a superficial elbow vein when a cuff with a known pressure was attached above the elbow and compared with the activity in the blood taken at the same moment from the control arm without any pressure.

1. Using a pressure 20 mm above the systolic pressure, no enhancement could be obtained in the first 10 minutes.

2. Using a diastolic or systolic pressure during 3 minutes, the fibrinolytic activity was about 2.8 times the activity in the control sample.

3. Using a pressure halfway the diastolic and systolic, the fibrinolytic activity after 3 minutes was about 3.5 times, and after 10 minutes about 11 times the activity in the control sample.

Repurposing Drugs in Oncology (ReDO)-chloroquine and hydroxychloroquine as anti-cancer agents

Chloroquine (CQ) and hydroxychloroquine (HCQ) are well-known 4-aminoquinoline antimalarial agents. Scientific evidence also supports the use of CQ and HCQ in the treatment of cancer. Overall, preclinical studies support CQ and HCQ use in anti-cancer therapy, especially in combination with conventional anti-cancer treatments since they are able to sensitise tumour cells to a variety of drugs, potentiating the therapeutic activity. Thus far, clinical results are mostly in favour of the repurposing of CQ. However, over 30 clinical studies are still evaluating the activity of both CQ and HCQ in different cancer types and in combination with various standard treatments. Interestingly, CQ and HCQ exert effects both on cancer cells and on the tumour microenvironment. In addition to inhibition of the autophagic flux, which is the most studied anti-cancer effect of CQ and HCQ, these drugs affect the Toll-like receptor 9, p53 and CXCR4-CXCL12 pathway in cancer cells. In the tumour stroma, CQ was shown to affect the tumour vasculature, cancer-associated fibroblasts and the immune system. The evidence reviewed in this paper indicates that both CQ and HCQ deserve further clinical investigations in several cancer types. Special attention about the drug (CQ versus HCQ), the dose and the schedule of administration should be taken in the design of new trials.

Adapt, Recycle, and Move on: Proteostasis and Trafficking Mechanisms in Melanoma

Melanoma has emerged as a paradigm of a highly aggressive and plastic cancer, capable to co-opt the tumor stroma in order to adapt to the hostile microenvironment, suppress immunosurveillance mechanisms, and disseminate. In particular, oncogene- and aneuploidy-driven dysregulations of proteostasis in melanoma cells impose a rewiring of central proteostatic processes, such as the heat shock and unfolded protein responses, autophagy, and the endo-lysosomal system, to avoid proteotoxicity. Research over the past decade has indicated that alterations in key nodes of these proteostasis pathways act in conjunction with crucial oncogenic drivers to increase intrinsic adaptations of melanoma cells against proteotoxic stress, modulate the high metabolic demand of these cancer cells and the interface with other stromal cells, through the heightened release of soluble factors or exosomes. Here, we overview and discuss how key proteostasis pathways and vesicular trafficking mechanisms are turned into vital conduits of melanoma progression, by supporting cancer cell's adaptation to the microenvironment, limiting or modulating the ability to respond to therapy and fueling melanoma dissemination.

Chloroquine anticancer activity is mediated by autophagy-independent effects on the tumor vasculature

Chloroquine is used clinically as an autophagy blocker to potentiate anticancer treatments. However, whether chloroquine acts solely through autophagy-dependent and cancer cell autonomous mechanisms has remained elusive. In a recent study we found that chloroquine reduced intratumoral hypoxia and metastasis, while improving chemotherapy response, largely through an autophagy-independent, NOTCH1-reliant mechanism of tumor vessel normalization.

Vesicular trafficking mechanisms in endothelial cells as modulators of the tumor vasculature and targets of antiangiogenic therapies

A common feature of solid tumors is their ability to incite the formation of new blood and lymph vessels trough the processes of angiogenesis and lymphangiogenesis, respectively, to support tumor growth and favor metastatic dissemination. As a result of the lack of feedback regulatory control mechanisms or due to the exacerbated presence of pro-angiogenic signals within the tumor microenvironment, the tumor endothelium receives continuous signals to sprout and develop, generating vessels that are structurally and functionally abnormal. An emerging mechanism playing a central role in shaping the tumor vasculature is the endothelial-vesicular network that regulates trafficking/export and degradation of key signaling proteins and membrane receptors, including the vascular endothelial growth-factor receptor-2/3 and members of the Notch pathway. Here we will discuss recent evidence highlighting how vesicular trafficking mechanisms in endothelial cells contribute to pathological angiogenesis/lymphangiogenesis and can provide novel and exploitable targets in antiangiogenic therapies.

How to teach an old dog new tricks: autophagy-independent action of chloroquine on the tumor vasculature

Chloroquine (CQ) is exploited in clinical trials as an autophagy blocker to potentiate anticancer therapy, but it is unknown if it solely acts by inhibiting cancer cell-autonomous autophagy. Our recent study shows that besides blocking cancer cell growth, CQ also affects endothelial cells (ECs) and promotes tumor vessel normalization. This vessel normalizing effect of CQ reduces tumor hypoxia, cancer cell intravasation, and metastasis, while improving the delivery and response to chemotherapy. By compromising autophagy in melanoma cells or using mice with a conditional knockout of ATG5 in ECs, we found that the favorable effects of CQ on the tumor vasculature do not rely on autophagy. CQ-induced vessel normalization relies mainly on altered endolysosomal trafficking and sustained NOTCH1 signaling in ECs. Remarkably these CQ-mediated effects are abrogated when tumors are grown in mice harboring EC-specific deletion of NOTCH1. The autophagy-independent vessel normalization by CQ leading to improved delivery and tumor response to chemotherapy further advocates its clinical use in combination with anticancer treatments.

Simultaneous Parenchyma-Preserving Liver Resection, Cytoreductive Surgery and Intraperitoneal Chemotherapy for Stage IV Colorectal Cancer

BACKGROUND

The outcome of stage IV colorectal cancer (CRC) has improved with modern systemic therapy. However, the concomitant presence of liver metastases (LM) and peritoneal carcinomatosis (PC) remains associated with a dismal prognosis and surgery in this context remains exceptional.

METHODS

Stage IV CRC patients with LM and PC undergoing simultaneous cytoreductive surgery, intraperitoneal chemotherapy (IPC) and liver resection/ablation were identified from prospectively collected databases. We assessed response to neoadjuvant chemotherapy (NACT), postoperative complications, progression free survival (PFS), and overall survival (OS).

RESULTS

Twenty-one patients with resectable disease were treated between 2007 and 2014. In 16 patients (76%), NACT was administered and tumour response defined their selection. The remaining 5 (24%) were selected according to the pattern of recurrence. Median peritoneal cancer index was 5 (range: 3-10.5). Liver surgery included 34 wedge resections, 5 ablations and one bisectionectomy to treat a total of 45 hepatic lesions with a median of 2 per patient (range: 1-2) and a median size of 1.35 cm (range: 0.8-2). Tumour regression grade 4 (fibrosis but residual cancer cells predominate) was seen in 50% of the resected metastases after NACT. Median hospital stay was 17 days (range: 14-24); severe morbidity (Clavien-Dindo grade 3-4) occurred in 24% and no perioperative mortality (0-90 days) was recorded. The median OS was 44 months (range: 31-57) while the median PFS was 10 months (range: 8-12).

CONCLUSIONS

Combined parenchyma-preserving liver resection, cytoreductive surgery and IPC in patients with LM and PC from CRC can be performed safely and results in promising mid-term overall survival.

Autophagy, a major adaptation pathway shaping cancer cell death and anticancer immunity responses following photodynamic therapy

Autophagy is fundamentally a cytoprotective and pro-survival process yet studies have shown that it has an exceedingly contextual role in cancer biology; depending on the phase, location or type of oncogenic trigger and/or therapy, its role could fluctuate from pro- to anti-tumourigenic.

Conservative treatment of spontaneous dissection of the subclavian artery

Dissection of the subclavian artery usually occurs as a result of trauma, endovascular interventions or connective tissue disorders. Only rarely has it been described occurring spontaneously. The treatment can be endovascular, open surgery, conservative or a combination of the above. There are no guidelines. The best approach is the one tailored to the lesion itself. This case presents a 73-year-old man with a tiresome and heavy feeling in the right arm. He was diagnosed having a spontaneous dissection of the right subclavian artery, accompanied by a complete occlusion more distally. Because of the relatively minor symptoms he was treated conservatively using anticoagulants. After 6 months of treatment there was complete revascularisation with good pulsations at the right wrist.

Conservative Treatment of Spontaneous Dissection of the Subclavian Artery

Dissection of the subclavian artery usually occurs as a result of trauma, endovascular interventions or connective tissue disorders. Only rarely has it been described occurring spontaneously. The treatment can be endovascular, open surgery, conservative or a combination of the above. There are no guidelines. The best approach is the one tailored to the lesion itself. This case presents a 73-year-old man with a tiresome and heavy feeling in the right arm. He was diagnosed having a spontaneous dissection of the right subclavian artery, accompanied by a complete occlusion more distally. Because of the relatively minor symptoms he was treated conservatively using anticoagulants. After 6 months of treatment there was complete revascularisation with good pulsations at the right wrist.

Targeting the hallmarks of cancer with therapy-induced endoplasmic reticulum (ER) stress

The endoplasmic reticulum (ER) is at the center of a number of vital cellular processes such as cell growth, death, and differentiation, crosstalk with immune or stromal cells, and maintenance of proteostasis or homeostasis, and ER functions have implications for various pathologies including cancer. Recently, a number of major hallmarks of cancer have been delineated that are expected to facilitate the development of anticancer therapies. However, therapeutic induction of ER stress as a strategy to broadly target multiple hallmarks of cancer has been seldom discussed despite the fact that several primary or secondary ER stress-inducing therapies have been found to exhibit positive clinical activity in cancer patients. In the present review we provide a brief historical overview of the major discoveries and milestones in the field of ER stress biology with important implications for anticancer therapy. Furthermore, we comprehensively discuss possible strategies enabling the targeting of multiple hallmarks of cancer with therapy-induced ER stress.

Dynamic interplay between autophagic flux and Akt during melanoma progression in vitro

Despite advances in cancer diagnosis and therapy, metastatic melanoma remains untreatable, due to its notorious resistance to apoptosis, deeming traditional therapies obsolete. Deregulated PI3K/Akt signalling is a common oncogenic event enabling melanocyte transformation and represents a significant and 'druggable' pathway in melanoma. Emerging data show that the ability of cancer cells to survive is also facilitated by alteration of vital homoeostatic mechanisms, such as autophagy. Although the role of autophagy in melanoma is still controversial, recent studies suggest that basal autophagy is down-modulated in primary melanomas. However, the dynamic connection between pro-tumorigenic PI3K/Akt and autophagy during melanoma progression has not been systematically studied. By using human primary melanocytes, incipient melanoma and metastatic melanoma cell lines, we show that early in melanomagenesis, increased Akt activity is associated with a low baseline autophagic flux. However, during melanoma progression, metastatic melanoma cells regain the ability to stimulate autophagic flux, supporting survival. Heightened autophagy is associated with an attenuated Akt activation status and can be suppressed by overexpressing a constitutive active mutant of Akt. On the other hand, blocking the higher Akt activity of primary melanoma is sufficient to incite autophagy. Interestingly, we found that although Akt supports survival of melanocytes and all melanoma cell lines, autophagy inhibition specifically targeted the metastatic melanoma cells, thus indicating a stage-specific requirement for Akt and autophagic flux, throughout melanoma progression. Therefore, this study highlights a dynamic interplay between Akt signalling and autophagic rescue in melanoma, which should be considered in the design of therapeutic strategies targeting these pathways.

Tumor vessel normalization by chloroquine independent of autophagy

Chloroquine (CQ) has been evaluated as an autophagy blocker for cancer treatment, but it is unknown if it acts solely by inhibiting cancer cell autophagy. We report that CQ reduced tumor growth but improved the tumor milieu. By normalizing tumor vessel structure and function and increasing perfusion, CQ reduced hypoxia, cancer cell invasion, and metastasis, while improving chemotherapy delivery and response. Inhibiting autophagy in cancer cells or endothelial cells (ECs) failed to induce such effects. CQ's vessel normalization activity relied mainly on alterations of endosomal Notch1 trafficking and signaling in ECs and was abrogated by Notch1 deletion in ECs in vivo. Thus, autophagy-independent vessel normalization by CQ restrains tumor invasion and metastasis while improving chemotherapy, supporting the use of CQ for anticancer treatment.

Autophagy and mitophagy interplay in melanoma progression

Autophagy, or self-eating, is the most extensively studied lysosomal degradation pathway for the recycling of obsolete or damaged cytoplasmic materials, including proteins and organelles. Although this pathway was initially thought to function as trafficking system for 'in bulk' degradation by the lysosomes of cytoplasmic material, it is now widely appreciated that cargo selection by the autophagic machinery is a major process underlying the cytoprotective or--possibly--pro-death functions ascribed to this catabolic process. Indeed increasing evidence suggests that in mammalian cells the removal of dysfunctional or aged mitochondria occurs through a selective degradation pathway known as 'mitophagy'. Due to the crucial role of mitochondria in energy metabolism, redox control and cell survival/death decision, deregulated mitophagy can potentially impact a variety of crucial cell autonomous and non-autonomous processes. Accumulating evidence indicates that during malignant transformation aggressive cancers hijack autophagy to preserve energy fitness and to acquire the plasticity required to adapt to the hostile microenvironment. However, whether and how mitophagy contributes to carcinogenesis, which pathways regulate this process in the cancer cells and how cancer cell-mitophagy impacts and modifies the tumor microenvironment and therapeutic responses, remain largely unanswered issues. In this review, we discuss novel paradigms and pathways regulating mitophagy in mammalian cells and the impact this process might have on one of the most dreadful human malignancies, melanoma.

The human melanoma side population displays molecular and functional characteristics of enriched chemoresistance and tumorigenesis

Melanoma remains the most lethal skin cancer, mainly because of high resistance to therapy. Side population (SP) cells are found in many types of cancer and are usually enriched in therapy-resistant as well as tumorigenic cells. Here, we identified a Hoechst dye-effluxing SP in a large series of human melanoma samples representing different progression phases. The SP size did not change with disease stage but was correlated with the prognostic “Breslow’s depth” in the primary (cutaneous) tumors. When injected into immunodeficient mice, the SP generated larger tumors than the bulk “main population” (MP) melanoma cells in two consecutive generations, and showed tumorigenic capacity at lower cell numbers than the MP. In addition, the SP reconstituted the heterogeneous composition of the human A375 melanoma cell line, and its clonogenic activity was 2.5-fold higher than that of the MP. Gene-expression analysis revealed upregulated expression in the melanoma SP (versus the MP) of genes associated with chemoresistance and anti-apoptosis. Consistent with these molecular characteristics, the SP increased in proportion when A375 cells were exposed to the melanoma standard chemotherapeutic agent dacarbazine, and to the aggravating condition of hypoxia. In addition, the SP showed enhanced expression of genes related to cell invasion and migration, as well as to putative (melanoma) cancer stem cells (CSC) including ABCB1 and JARID1B. ABCB1 immunoreactivity was detected in a number of tumor cells in human melanomas, and in particular in clusters at the invasive front of the primary tumors. Together, our findings support that the human melanoma SP is enriched in tumorigenic and chemoresistant capacity, considered key characteristics of CSC. The melanoma SP may therefore represent an interesting therapeutic target.

Skin mild hypoxia enhances killing of UVB-damaged keratinocytes through reactive oxygen species-mediated apoptosis requiring Noxa and Bim

The naturally occurring skin hypoxia has emerged as a crucial host factor of the epidermal microenvironment. We wanted to systematically investigate how reduced oxygen availability of the epidermis modulates the response of keratinocytes and melanocytes to noxious ultraviolet B radiation (UVB). We report that the exposure of normal human keratinocytes (NHKs) or melanocytes (NHEMs) to mild hypoxia drastically impacts cell death responses following UVB irradiation. The hypoxic microenvironment favors survival and reduces apoptosis of UVB-irradiated NHEMs and their malignant counterparts (melanoma cells). In contrast, NHKs, but not the transformed keratinocytes, under hypoxic conditions display increased levels of reactive oxygen species (ROS) and are significantly sensitized to UVB-mediated apoptosis as compared to NHKs treated under normoxic conditions. Prolonged exposure of UVB-treated NHKs to hypoxia triggers a sustained and reactive oxygen species-dependent activation of the stress kinases p38(MAPK) and JNKs, which in turn, engage the activation of Noxa and Bim proapoptotic proteins. Combined silencing of Noxa and Bim significantly inhibits UVB-mediated apoptosis under hypoxic conditions, demonstrating that hypoxia results in an amplification of the intrinsic apoptotic pathway. Physiologically occurring skin hypoxia, by facilitating the specific removal of UVB-damaged keratinocytes, may represent a decisive host factor impeding important steps of the photocarcinogenesis process.

Models for the longitudinal genetic analysis of same-age twins: application to HDL cholesterol

Models are presented for the analysis of longitudinal data from same-age twins which permit the exploration of a remarkably diverse array of alternative explanations for continuity and change during development. Data of this type permit the detection of new sources of genetic or environmental covariation during development that are not expressed at earlier ages and, because they include the effects of age-specific genes, the resulting heritability estimates are more reliable than those obtained from relatives who differ in age. The proposed models were applied to measurements of HDL cholesterol obtained on 81 pairs of monozygotic (MZ) twins and 69 dizygotic (DZ) pairs at 11, 12.5 and 14 years of age. All three MZ co-twin correlations were substantially higher than the self correlations across occasions, suggesting that new sources of genetic or environmental covariation must be expressed during early adolescence. This interpretation was confirmed by analysis of the full covariance matrices which showed that only models which assumed the expression of new or age-specific genes could explain the observed pattern of covariation. Because they include the effects of age-specific genes, the resulting heritabilities (0.80–0.83) were substantially higher than many previous estimates.

Uncovering the role of hypoxia inducible factor-1α in skin carcinogenesis

The hypoxia inducible factor-1α (HIF-1α) is a pleiotropic transcription factor typically activated in response to low oxygen tension as well as other stress factors in normoxic conditions. Upon activation HIF-1α mediates the transcriptional activation of target genes involved in a variety of processes comprising stress adaptation, metabolism, growth and invasion, but also apoptotic cell death. The molecular mechanisms, signaling pathways and downstream targets evoked by the activation of HIF-1α in epidermal cells are becoming increasingly understood and underscore the participation of HIF-1α in crucial processes including malignant transformation and cancer progression. Recent studies have implicated HIF-1α as an integral part of the multifaceted signal transduction initiated by the exposure of keratinocytes to ultraviolet radiation B (UVB), which represents the most ubiquitous hazard for human skin and the principal risk factor for skin cancer. HIF-1α activation by UVB exposure contributes to either repair or the removal of UVB-damaged keratinocytes by inducing apoptosis, thus revealing a tumor suppressor role for HIF-1α in these cells. On the other hand, the constitutive expression of HIF-1α evoked by the mild hypoxic state of the skin has been implicated as a positive factor in the transformation of normal melanocytes into malignant melanoma, one of the most aggressive types of human cancers. Here we review the uncovered and complex role of HIF-1α in skin carcinogenesis.

[Prevalence of mood disorders in Parkinson's disease patients treated with subthalamic nucleus deep brain stimulation]

Subthalamic nucleus deep brain stimulation (STN-DBS) is a recognized treatment for advanced and severe forms of Parkinson's Disease. The procedure improves motor signs and often allows a reduction of the medication. The impact of the procedure on cognitive and neuropsychiatric signs of the disease is more debated and there is an international consensus for the need of a multidisciplinary evaluation of patients undergoing such programs, including a neuropsychiatric assessment. We present a review of the literature as well as the experience at our centre focused on the short and long term outcome on mood following STN-DBS.

ROS-mediated mechanisms of autophagy stimulation and their relevance in cancer therapy

Mounting evidence suggests that reactive oxygen species (ROS) are multifaceted signaling molecules implicated in a variety of cellular programs during physiological as well as pathological conditions. Recently, ROS produced endogenously, by deranged metabolism of cancer cells, or exogenously, by ROS-generating drugs, have been shown to promote macroautophagy, a lysosomal pathway of self-degradation with essential prosurvival functions. Several molecular aspects of the modulation of autophagy pathways by ROS have been revealed in the past years and it is now clear that these processes are mutually linked and play a crucial role in cancer progression and in response to cancer therapeutics. In this review we address the molecular mechanisms underlying the activation of autophagy pathways by ROS and focus on the role of autophagy in cancer cells responding to ROS-producing agents, which are utilized as a therapeutic modality to kill cancer cells.

A Phase II Study of the Combination of Endocrine Treatment and Bortezomib in Patients with Endocrine Resistant Metastatic Breast Cancer

Background: The introduction of anti-hormonal treatment has been a major revolution in breast cancer management. The majority of patients with metastatic hormone receptor-positive breast cancer eventually suffer from progression of their disease despite different types of anti-hormonal treatment. Preclinical studies have indicated bidirectional inhibitory interactions between ER and NF-kappaB, governing in part endocrine-resistance and enhanced growth. The hypothesis that inhibition of NF-kappaB activation by a proteasome inhibitor might reverse the sensitivity to endocrine therapy was the rationale to initiate a phase II trial.Aim, Material and Methods: The aim is to investigate whether the addition of open label bortezomib to either a SERM or an AI will result in documented activity in patients with progressive and measurable disease on the identical endocrine agent. This endpoint is evaluated according to RECIST criteria every 8 weeks. The patients are stratified into 2 treatment groups, according to their current endocrine treatment either tamoxifen or an AI. Bortezomib is administered on days 1, 8, 15, 21 of a 6 week regimen at a dose of 1.6 mg/sqm on each treatment day. Consecutive tumour biopsies (if accessible) and blood samples are collected for translational purposes. Clinical benefit was predefined by the patients obtaining at least either stable disease, or a partial or a complete response according to RECIST criteria, lasting for at least four weeks. A two-stage statistical approach showed that this should at least occur in 1 patient in the first cohort of 14 patients, prior to further accrual.Results: At present N=9 patients have been enrolled. Eight patients received AI+bortezomib, while one received TAM+bortezomib. N=5/9 patients had progressive disease, N=4/9 patients had stable disease of which two patients (N=2/9) had stable disease continuing for more than 4 weeks. There were no objective antitumour responses observed. N=4/9 had grade III diarrhoea. Median time to treatment failure was 69 days [35-140], either due to toxicity (N=3/9) or (eventual) progression (N=6/9).Conclusions: Preliminary results shows that the clinical benefit rate is 22% (N=2/9). Although preliminary, these results warrant further accrual and suggest that the biological hypothesis seems clinically valid. Further recruitment is ongoing.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 4099.

Deregulation of cell-death pathways as the cornerstone of skin diseases

Deregulation of cell-death pathways plays a key role in the pathogenesis of various skin diseases. The different types of cell death are mainly defined by morphological criteria, and include apoptosis, autophagic cell death, and necrosis. The process of apoptosis is well characterized at the molecular level and involves the activation of two main pathways, the intrinsic and extrinsic pathways, converging into the execution of apoptosis by intracellular cysteine proteases, called caspases. The relevance and implication of these apoptotic pathways in the pathophysiology of skin diseases, such as toxic epidermal necrolysis, graft-versus-host disease and skin cancer, has been extensively studied. The role of autophagic cell death in progression of skin tumours and response to cytotoxic drugs is only beginning to be elucidated.

Circulating tumor cell detection: A direct comparison between the CellSearch System, the AdnaTest, and CK-19/mammaglobin RT-PCR in patients with metastatic breast cancer

e22117

Background: The detection, enumeration and isolation of circulating tumor cells (CTC) has considerable potential to influence the clinical management of patients with breast cancer. There is however a substantial variability in the rates of positive samples using existing detection techniques. Methods: This study was designed to compare three techniques for detecting CTC in blood of 80 patients with metastatic breast cancer (MBC) and 20 healthy controls: the CellSearch System, which is an automated, standardized and regulatory-approved system for the immunocytochemical detection and quantification of CTC in blood; ii) the AdnaTest Breast Cancer Select/Detect, which involves the detection of tumor-associated transcripts by RT-PCR after an immunomagnetically enrichment of tumor cells; iii) an in-house developed multimarker qRT-PCR assay, which involves the quantification of tumor-associated transcripts (CK-19 and MAM) by qRT- PCR. Results: As a result, 23% of patients with MBC were positive by the CellSearch System (≥5 CTC), 22% by the AdnaTest (>0.30 ng/μl for any of the amplicons), 31% by qRT-PCR for CK-19 and 49% by qRT-PCR for MAM. Samples were more likely to be positive by qRT-PCR for at least one mRNA marker than by the CellSearch System (P<0.001) or the AdnaTest (P <0.001). The concordance between samples analyzed by the CellSearch System and the AdnaTest was substantial (κ = 0.667, P <0.001). Agreement between both detection techniques was observed in 88% of blood samples. When the CellSearch System was compared with the qRT-PCR assays for CK-19 and MAM, we observed agreement percentages of 78% and 58%, respectively (κ = 0.462, P <0.001 and κ = 0.159, P = 0.09). Agreement between the AdnaTest and the qRT-PCR assays for CK-19 and MAM was observed in 78% and 53% of blood samples, respectively (κ = 0.443, P <0.001 and κ = 0.05, P = 0.607). Conclusions: We observed a substantial variation in the detection rates of CTC in blood from MBC patients using three different techniques. A higher rate of positive samples was observed using a combined qRT-PCR approach for CK-19 and MAM, which suggests that this is currently the most sensitive technique for detecting CTC.

No significant financial relationships to disclose.

The presence of circulating total DNA and methylated genes is associated with circulating tumour cells in blood from breast cancer patients

Circulating tumour cells (CTC) and tumour-related methylated DNA in blood have been separately assessed for their utility as a marker for subclinical metastasis in breast cancer. However, no studies have looked into the relation between the both molecular markers in this type of cancer. In this study, we investigated the correlations between total/methylated DNA and CTC in the blood from metastatic breast cancer patients. We simultaneously obtained whole blood, plasma and serum samples from 80 patients and 20 controls. The CellSearch System was used to enumerate CTC in blood samples. Plasma total DNA levels were determined by a QPCR method. Sera were analysed by methylation-specific QPCR for three markers: adenomatous polyposis coli (APC), ras association domain family protein 1A (RASSF1A) and oestrogen receptor 1 (ESR1). Total DNA levels in patients were significantly increased when compared with controls (P<0.001) and correlated with the number of CTC (r=0.418, P<0.001). Hypermethylation of one or more genes was detected in 42 (53%) serum samples from breast cancer patients and in three (16%) serum samples from controls (P=0.003). APC was hypermethylated in 29%, RASSF1A in 35% and ESR1 in 20% of breast cancer cases. Detection of a methylated gene in serum was associated with the detection of CTC in blood (P=0.03). The detection of large amounts of circulating total/methylated DNA correlated with the presence of CTC in the blood from patients with breast cancer. This can be interpreted in two ways: (a) CTC are a potential source of circulating tumour-specific DNA; (b) high numbers of CTC and circulating methylated DNA are both a phenotypic feature of more aggressive tumour biology.

Circulating tumour cell (CTC) detection: a direct comparison between the CellSearch system, the AdnaTest, CK19/MAM RT-PCR and unmethylated/methylated free DNA in patients with metastatic breast cancer

Abstract #5025

Introduction: The detection, enumeration and isolation of CTC has considerable potential to influence the clinical management of patients with breast cancer. There is however a substantial variability in the rates of positive samples using existing detection techniques. This study was designed to compare the sensitivities and specificities of three techniques for detecting CTC in blood of patients with metastatic breast cancer (MBC). Furthermore, correlations between CTC and circulating total and tumor-related methylated DNA were investigated.&#x2028; Material and Methods: The presence of CTC in blood samples of 80 patients with MBC and 20 healthy controls was assessed by two commercial systems: i) the CellSearch System (Veridex LLC, Warren, NJ), in which epithelial cells are immunomagnetically separated and fluorescently labeled, and nucleated (DAPI+) cells with the EpCAM+, cytokeratin (CK) 8/18/19+, and CD45- phenotype are counted as CTC and ii) the AdnaTest and a real-time qRT-PCR assay for the detection of CK-19 and mammaglobin (MAM) transcripts. Plasma total DNA levels were measured by a qPCR method. Sera were analyzed by methylation-specific qPCR for three methylated markers: APC, RASSF1A and ESR1. The results obtained with AdnaTest are being analyzed and will be presented at the meeting.&#x2028; Results: Numbers of CTC identified by the CellSearch test were significantly higher in blood samples of patients with MBC than in healthy controls: the median number of CTC detected in 7.5 ml of blood was 1 (range 0-2617) in patients with MBC and 0 (range 0-1) in controls (P&lt;0.001). Using ≥2 cells as a threshold for positivity, which corresponds to 100% specificity in the control population, 34% of samples from patients with MBC were positive with the CellSearch test. Using a cut-off to ensure 100% specificity in the control population, 31% of patients were positive for CK-19, 49% for MAM and 61% for CK-19 and/or MAM by qRT-PCR. When the CellSearch test and the qRT-PCR for CK-19 and MAM were compared, the concordance was 57%. Positive samples with the CellSearch test, but not with the qRT-PCR assay, also showed significantly higher levels of circulating total DNA and were more likely to be positive for one of the methylated DNA markers in serum.&#x2028; Conclusion : We observed a substantial variation in the detection rates of CTC in blood from breast cancer patients using different techniques. A higher rate of positive samples was observed using a combined qRT-PCR approach for CK-19 and MAM, which suggests that this is currently the most sensitive technique for detecting CTC.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 5025.

Angiogenic escape and tumour progression in two patients with metastatic breast cancer receiving bevacizumab treatment

Abstract #1029

Background: Vascular endothelial growth factor A (VEGF-A) has an important role in tumour progression by promoting angiogenesis. VEGF-A inhibitors, such as bevacizumab (Bev) and VEGF-Trap are being introduced into the treatment of breast cancer in order to target angiogenesis by inhibiting VEGF-A.&#x2028; Material and Methods: Two patients with metastatic breast cancer are described having tumour progression while being treated with single agent Bev. Both patients participated in the AVADO clinical phase III study, where shown to have received Bev in combination with docetaxel (D) as first line treatment for metastatic breast cancer. The first patient (A) had received 6 cycles of D and Bev and was for 4 months on single agent Bev (15mg/kg/3wk) before progressing. Pt B had received 9 cycles of D and Bev and was on 7 months of single agent Bev (15mg/kg/3wk) before disease progression. Tumour biopsies of progressing lesions were obtained after informed consent. Routine histological assessment and a CD34/Ki67 double staining were performed on their primary tumour as well as on the newly developed metastasis (A+B). Chalkley counts (CC) and endothelial cell proliferation fractions (ECP) were assessed by two independent observers. RT-PCR Taqman low density arrays with a gene panel of 94 angiogenesis related genes were performed in triplicate on both metastasis and compared to 10 other primary breast tumours.&#x2028; Results: Both lesions showed a high CC, respectively 7.5±0.62 (A) and 4.8±0.2 (B). Both lesions had elevated ECP values of 14% (A) and 8% (B).&#x2028; Using the 2 (-__CT) method and 18S as an internal control, the VEGFR1 mRNA was highly overexpressed in both A (25.18±0.12 fold change) and B (38.60±0.07 fold change) compared to the mean of 10 unselected primary breast tumours serving as controls (p&lt;10-7). Similarly, in metastasis B, VEGF-B, TGFB1 and PDGFRA were found to be overexpressed, i.e. out of range [min-max] of the 10 primary breast tumours. A had out of range overexpression of VEGF-C. The gene expression of VEGF-A, VEGF-D, VEGFR2, VEGFR3, PDGFB and PDGFRB in both A and B were found to be in the range of the 10 controls.&#x2028; Conclusion: We describe two patients with progressive disease while being treated with Bev after an initial response on the combination of D and Bev. These new sites of disease showed a highly angiogenic and apparently vascular dependent growth pattern, in spite of high dosed anti-VEGF-A regimen. This suggests the existence of an important VEGF-A independent alternative modality of the tumour to promote angiogenesis. VEGFR1 was remarkably overexpressed in both metastases compared to controls. The expression of placental growth factor, a VEGFR1 specific ligand is further being explored. Knowledge of the biology of Bev resistance is essential since it could be useful in designing well considered combinations of targeted therapies.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 1029.

Heterogeneity among juvenile antisocial behaviours: findings from the Virginia Twin Study of Adolescent Behavioural Development

The examination of heterogeneity in antisocial behaviour was accomplished by applying latent class analytic methods to multivariate categorical data on 389 same-sex male twins, aged 11 to 16 from the Virginia Twin Study of Adolescent Behavioural Development (VTSABD). The data included multiple measures of oppositional and conduct disorder, attention deficit disorder, hyperactivity, impulsivity, reading disability and anxiety from mother, teacher, and child report from both questionnaire and interview (child and adult psychiatric assessment; CAPA). A latent four-class model provided a good fit to the data and yielded four phenotypically and aetiologically distinct latent classes: (1) a non-symptomatic class influenced by both additive genetic and shared environmental factors; (2) a hyperactivity-conduct disturbance class accounted for by both additive and non-additive genetic effects; (3) a 'pure' conduct disturbance class with a very strong shared environmental component; and (4) a multisymptomatic class explained entirely by the additive effect of the genes. Further characterization of these four latent classes by age of the child and parental psychiatric history is also shown.

Event-related potential correlates selectively reflect cognitive dysfunction in schizophrenics

Schizophrenics show event-related potential (ERP) and particularly P3 abnormalities. To study the more detailed relationships between these ERP alterations and cognitive dysfunction we recorded and analyzed ERPs using a particular experimental approach. In 34 schizophrenics and 25 controls ERPs were obtained by a visual Go/Nogo task requiring response inhibition and were decomposed into temporally independent topographical components using Independent Component Analysis (ICA). ICA disentangled different subcomponents of P3. Subcomponent P3b with a parietal maximum amplitude was significantly reduced in the schizophrenics, probably reflecting their attentional deficits. Subcomponent P3ng with a frontal maximum amplitude and enhanced during Nogo condition appeared as an electrophysiological index of response inhibition. A significantly reduced P3ng enhancement, found in schizophrenics, probably reflects their impaired response control.

CONCLUSIONS

ICA can successfully identify ERP subcomponents with distinct scalp topographies representing significant differential indices of normal and abnormal cognitive processing. Involvement of frontal brain areas in disturbed executive control in schizophrenics is supported by our ICA findings.

Gender differences in binge-eating: a population-based twin study

OBJECTIVE

To assess whether genetic and environmental effects on liability to binge-eating (BE) are of equal importance for males and females and whether the same genetic risk factors predispose to BE in the two sexes.

METHOD

Questionnaire data on 8045 same sex and opposite sex twins, aged 19-31 years, from a population-based Norwegian registry, was used to estimate the relative contribution of genetic and environmental factors to liability for BE utilizing structural equation modeling.

RESULTS

In the best-fitting model, the magnitude of genetic and environmental effects on BE was the same for males and females. Heritability was 51%. The correlation between genetic risk factors in men and women was estimated to be +0.57.

CONCLUSION

Binge-eating appears to be equally heritable in males and females. Although the majority of the genetic risk factors are shared between the sexes, there may exist gender-specific genetic effects on liability.

Auditory and visual event-related potentials in alcoholics: abnormalities of components and brain electrical field

Alterations of ERPs recorded over midline scalp sites have frequently been reported in alcoholics. To assess the P3 and other ERP components topographically, auditory and visual ERPs were recorded from 33 scalp electrodes in abstinent alcoholics and healthy controls using an oddball paradigm. At the Cz electrode the alcoholics showed decreased visual N1 and increased auditory N2 amplitudes. Topographically, the negative centroids of the visual N1 and P3 and the auditory N2 differed between groups, and the positive centroid of the visual P3 was displaced toward the right hemisphere. While no valid diagnostic classification could be obtained by using the traditional ERP component P3 recorded from Pz, the combination of visual N1 and auditory N2 amplitudes at Cz with centroid parameters amounted to 51% explained variance and 92% correct discrimination of alcoholics from controls. Abnormalities of N1 amplitude and P3 topography similar to the current findings in alcoholics have previously been described for schizophrenics.

Genetic and environmental causes of covariation in interview assessments of disruptive behavior in child and adolescent twins

Multirater, face-to-face, interview data relating to conduct disorder (CD), oppositional-defiant disorder (ODD), and inattentive, impulsive, and hyperactive components of attention-deficit hyperactivity disorder (ADHD) in a population-based sample of 1376 pairs of 8- to 16-year-old MZ and DZ twins are analyzed to examine (1) the genetic and environmental causes of correlation among ratings of ODD and CD symptoms and (2) the pattern of genetic and environmental correlation among the three components of ADHD. Parental ratings of ADHD showed marked sibling contrast effects, specific within raters but partly common across components. After these effects were removed, there was a modest genetic correlation between maternal and paternal ratings, but genetic effects were virtually uncorrelated across boys and girls. Genetic correlations among inattention, impulsivity, and hyperactivity were all large but fell well short of unity. There was little evidence that counts of symptoms of CD and ODD were genetically independent but the genetic correlations among ratings of twins, mothers, and fathers were all relatively modest. ODD and CD showed much higher genetic correlations across sexes than did the measures of ADHD. There was no evidence of rater contrast effects or of shared family environment influences in the twin resemblance for ODD and CD.

An evaluation of different approaches for behavior genetic analyses with psychiatric symptom scores

We used a simulation study to evaluate six approaches for behavior genetic analyses of psychiatric symptom scores. For the selection of the correct model, the best results were obtained with approaches using transformed scores in combination with a procedure involving p-values. With normalizing transformations, the chi 2 test statistic gave a reasonable impression of the overall fit of the model but was less accurate when used as a difference test. The asymptotic distribution free estimation methods yielded chi 2s that were much too large. All data analysis techniques yielded substantially biased parameter estimates. The most biased results were obtained with normalizing transformations. The least biased results were obtained with tobit correlations, but because of its large standard errors the most precise estimates were obtained with polychoric correlations and optimal scale scores. An empirical study showed that a recognition of the role of methodological factors was helpful to understand part of the differences between assessment instruments, raters, and data analysis techniques that were found in the real data.

Identification of new HER2/neu-derived peptide epitopes that can elicit specific CTL against autologous and allogeneic carcinomas and melanomas

Twenty-two new HLA-A2.1-binding peptides derived from the protooncogene HER2/neu were identified and analyzed for their capacity to elicit peptide and tumor-specific CTL responses. We used peptide-pulsed autologous DC from the ascites of patients with ovarian carcinomas to induce CTL. Of the 22 tested new HER2/neu-derived epitopes that could bind HLA-A2 with high (IC50 < 50 nM) or intermediate (50 nM < IC50 < 500 nM) affinity, we report the recognition by CTL of at least four novel epitopes, including HER2(9435), HER2(9665), HER2(9689), and HER2(10952), and confirm that of the known HER2 (9369) epitope. These epitopes were able to elicit CTL that specifically killed peptide-sensitized target cells and, most importantly, a HER2/neu-transfected cell line and the autologous tumor cells. We also confirm that HER2/neu is overexpressed in several melanoma lines, and as a new finding, report that some of these lines are sensitive to CTL induced by the HER2 (9369), HER2(9435), and HER2(9689) epitopes. Finally, CTL clones specific for HER2 (9369), HER2(9435), and HER2(9689) epitopes were isolated from tumor-specific CTL lines, further demonstrating the immunodominance of these epitopes. These findings broaden the potential application of HER2/neu-based immunotherapy.

Comparing the biological and cultural inheritance of personality and social attitudes in the Virginia 30,000 study of twins and their relatives

Measures of four dimensions of personality (Psychoticism, Extraversion, Neuroticism, and Lie scores) and six aspects of social attitudes (to sex, taxation, militarism, politics, religion and a general conservatism scale) were obtained by mailed questionnaire from 29,691 US subjects including adult twins (n = 14,761) their parents (n = 2360), their spouses (n = 4391), siblings (n = 3184) and adult children (n = 4800). After correction for the average effects of age, sex and source of sample, familial correlations were computed for 80 distinct biological and social relationships. The data allow for the estimation of the additive and non-additive effects of genes, assortative mating, vertical cultural inheritance and other non-parental effects of the shared environment on differences in personality and social attitudes. The interaction of genetic and environmental effects with sex may also be analyzed. Model-fitting analyses show that personality and social attitude measures differ markedly in major features of family resemblance. Additive and dominant genetic effects contribute to differences in both personality and attitudes, but the effects of the family environment, including vertical cultural transmission from parent to child, are much more marked for social attitudes than for personality. There is substantial assortative mating for social attitudes and almost none for personality. The causes of family resemblance depend significantly on sex for almost every variable studied. These findings clarify and extend the more tentative findings derived from previous twin, family and adoption studies.

The influence of genetic factors and life stress on depression among adolescent girls

BACKGROUND

The possible causes of greater depression among adolescent girls were investigated by examining variation in the influence of genetic and environmental risk factors among 182 prepubertal female, 237 prepubertal male, 314 pubertal female, and 171 pubertal male twin pairs from the Virginia Twin Study of Adolescent Behavioral Development.

OBJECTIVES

To compare the trajectory of depressive symptoms among boys and girls from childhood to adolescence; to analyze the role of genetic, shared, and unique environmental factors in depression among prepubertal and pubertal male and female twins; and to investigate a possible link between liability to depression and one salient index of the child's environment: past-year life events.

METHODS

Child-reported depression was assessed using the Child and Adolescent Psychiatric Interview and ratings of past-year life events and pubertal status obtained by maternal questionnaire and interview, respectively.

RESULTS

The impact of life events on depression was particularly evident in the adolescent girls. The results from model fitting indicate increased heritability for depression in this group, and its long-term consistency was mediated primarily by latent genetic factors. Model fitting also showed that at least part of the liability to depression and to life events can be linked to a common set of genes in the adolescent girls, and there is a notable developmental increase in the genetic variance for life events.

CONCLUSIONS

The greater heritability for depression in pubertal girls, its genetic mediation over time, and the increase in genetic variance for life events may be one possible explanation for the emergence of increased depression among pubertal girls and its persistence through adolescence.