Mutational Activation of the NRF2 Pathway Upregulates Kynureninase Resulting in Tumor Immunosuppression and Poor Outcome in Lung Adenocarcinoma.

Activation of the NRF2 pathway through gain-of-function mutations or loss-of-function of its suppressor KEAP1 is a frequent finding in lung cancer. NRF2 activation has been reported to alter the tumor microenvironment. Here, we demonstrated that NRF2 alters tryptophan metabolism through the kynurenine pathway that is associated with a tumor-promoting, immune suppressed microenvironment. Specifically, proteomic profiles of 47 lung adenocarcinoma (LUAD) cell lines (11 KEAP1 mutant and 36 KEAP1 wild-type) revealed the tryptophan-kynurenine enzyme kynureninase (KYNU) as a top overexpressed protein associated with activated NRF2. The siRNA-mediated knockdown of NFE2L2, the gene encoding for NRF2, or activation of the NRF2 pathway through siRNA-mediated knockdown of KEAP1 or via chemical induction with the NRF2-activator CDDO-Me confirmed that NRF2 is a regulator of KYNU expression in LUAD. Metabolomic analyses confirmed KYNU to be enzymatically functional. Analysis of multiple independent gene expression datasets of LUAD, as well as a LUAD tumor microarray demonstrated that elevated KYNU was associated with immunosuppression, including potent induction of T-regulatory cells, increased levels of PD1 and PD-L1, and resulted in poorer survival. Our findings indicate a novel mechanism of NRF2 tumoral immunosuppression through upregulation of KYNU.

Applicability of sentinel lymph node biopsy in papillary thyroid cancer.

BACKGROUND: The optimal surgical management of papillary thyroid cancer (PTC) for T1-T2 tumors without pre or intrasurgical evidence of lymph node metastasis (cN0) remains controversial, since approximately 40% of patients have lymph node involvement (pN1) which becomes evident when a prophylactic lymphadenectomy (PL) is performed. The aim of this study was to investigate the feasibility of sentinel lymph node (SLN) identification with SPECT/CT lymphoscintigraphy imaging along with intraoperatory image techniques in early stages of PTC undergoing PL of central neck compartment (CNC). METHODS: A single-center, prospective consecutive study was designed for SLN mapping in patients with high suspicion of PTC (Bethesda V or VI) in early stage (cT1-2, cN0). Twenty-four patients underwent SLN identification with preoperative SPECT/CT and planar images (99mTc-nanocolloid albumin intratumoral injection). During surgery, SLN located in CNC was found by means of a gamma probe and portable gamma camera, and excised. Afterwards, CNC lymphadenectomy was performed in all cases without modifying the established protocol. RESULTS: SLNs were identified and accurately located in 23 (95.8%) patients. Nodal metastases (pN1) were confirmed in 9 (37.5%) patients, with one false negative case. The sensitivity was 88.9% and negative predictive value (NPV) was 93.3%, would have allowed to avoid PL in more than half of cases, a higher proportion than those found in other similar studies. No complications associated with the procedure were observed. CONCLUSIONS: Our results support that SLN biopsy by SPECT/CT along with intraoperatory image techniques is applicable in early stages of PTC (cT1-2, cN0), allowing to avoid unnecessary PL.

Cirugía endocrina cervical mínimamente invasiva / Minimally-invasive endocrine neck surgery

Los abordajes quirúrgicos mínimamente invasivos en cirugía endocrina cervical son el resultado del esfuerzo de varios cirujanos para extrapolar los beneficios comprobados de técnicas mínimamente invasivas en otras regiones del cuerpo, como la reducción del dolor, la morbilidad y el tiempo de hospitalización. Sin embargo, el principal argumento que condujo a la introducción de estas técnicas fue la mejora de los resultados estéticos. Los abordajes endoscópicos y robóticos a través de pequeñas incisiones se han desarrollado durante los últimos 25 años y continúan en un constante refinamiento. El objetivo de esta revisión es describir el estado actual de la literatura, a través de una evaluación sistemática, de las diferentes técnicas disponibles dentro de la cirugía endocrina cervical mínimamente invasiva ya sea con acceso cervical o remoto, describiendo sus características principales y evaluando sus ventajas, desventajas y controversias, para discutir finalmente su papel en la cirugía actual y el futuro que tienen estos procedimientos

Minimally invasive approaches for endocrine surgery of the neck are the result of efforts by several surgeons to extrapolate to neck surgery the proven benefits of minimally invasive techniques from other regions of the body, including less pain, morbidity and hospital stay. However, the main argument that led to the introduction of these techniques was the improvement of esthetic results. Endoscopic and robotic remote-access endocrine neck approaches through small incisions have been developed over the last 25 years and are constantly being refined. The objective of this review is to determine the current state of the literature through a systematic evaluation of the different techniques available in minimally invasive endocrine surgery of the neck, either with or without remote access, by describing their main characteristics and evaluating their advantages, disadvantages and controversies, while discussing their role and future in neck surgery

Minimally-invasive endocrine neck surgery. / Cirugía endocrina cervical mínimamente invasiva.

Minimally invasive approaches for endocrine surgery of the neck are the result of efforts by several surgeons to extrapolate to neck surgery the proven benefits of minimally invasive techniques from other regions of the body, including less pain, morbidity and hospital stay. However, the main argument that led to the introduction of these techniques was the improvement of esthetic results. Endoscopic and robotic remote-access endocrine neck approaches through small incisions have been developed over the last 25 years and are constantly being refined. The objective of this review is to determine the current state of the literature through a systematic evaluation of the different techniques available in minimally invasive endocrine surgery of the neck, either with or without remote access, by describing their main characteristics and evaluating their advantages, disadvantages and controversies, while discussing their role and future in neck surgery.

Tiroidectomía endoscópica transaxilar: un abordaje más que ofrecer a nuestros pacientes / Transaxillary endoscopic thyroidectomy: Another approach to offer our patients

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Preservación de corteza adrenal funcionante. Una buena razón para realizar un abordaje endoscópico retroperitoneal posterior / Functional adrenal cortex preservation: A good reason for posterior retroperitoneal endoscopic approach

INTRODUCCIÓN: La adrenalectomía con preservación cortical se indica como tratamiento del feocromocitoma bilateral hereditario y esporádico, en casos de bajo riesgo de malignidad, para reducir la posibilidad de insuficiencia suprarrenal asumiendo la eventualidad de una recidiva local. El objetivo del estudio es analizar los resultados funcionales de la adrenalectomía parcial por vía endoscópica retroperitoneal en pacientes monoadrenales o que necesiten una adrenalectomía bilateral. MÉTODOS: Entre enero de 2015 y febrero de 2016 se incluyeron de forma prospectiva pacientes con feocromocitoma asociado a mutaciones con bajo riesgo para malignidad, que aceptaron participar en el estudio. Todos fueron operados por cirujanos especialmente entrenados en este tipo de cirugía, utilizando la misma técnica quirúrgica. Se recogieron variables demográficas y características clínicas, realizando posteriormente el análisis descriptivo de dichas variables. RESULTADOS: Se registraron un total de 6 pacientes, cuatro asociados al síndrome MEN tipo 2 y dos en contexto del síndrome VHL. No fue precisa ninguna conversión a abordaje laparoscópico o abierto y tampoco complicaciones postoperatorias, la estancia hospitalaria media fue de 2,5 días. Se logró la preservación de corteza adrenal funcionante sin requerimiento corticoideo en 5 (83%) de 6 casos. Con un seguimiento medio de 26,2 ± 6 meses, estos 5 pacientes presentan una función adrenal conservada sin aporte hormonal sustitutivo. CONCLUSIONES: La adrenalectomía con preservación cortical por vía endoscópica retroperitoneal, en manos expertas, es segura y factible para el tratamiento del feocromocitoma hereditario y esporádico en contexto de baja malignidad, permitiendo evitar la necesidad de aporte corticoideo en la mayoría de los casos

INTRODUCTION: Cortical-sparing adrenalectomy is a suitable treatment for hereditary and sporadic bilateral pheochromocytoma, in cases of low risk of malignancy, to reduce the possibility of adrenal insufficiency assuming the chance of local recurrence. The aim of the study is to analyze the functional results of partial adrenalectomy by retroperitoneal endoscopic approach in single-adrenal patients or patients requiring bilateral adrenalectomy. METHODS: Prospective study between January 2015 and February 2016 including pheochromocytoma patients diagnosed with low risk of malignant mutations. All patients agreed to be included in the study. Experienced endocrine surgeons who have been trained in minimally invasive endocrine surgery performed the procedure using the same surgical technique. Demographic variables and clinical characteristics were collected, subsequently carrying out the descriptive analysis of the data. RESULTS: A total of 6 patients were registered, four associated with MEN type 2 syndrome and two in the context of VHL syndrome. Retroperitoneoscopic resection was performed without laparoscopic or open conversion and no postoperative complications; the average hospital stay was 2.5 days. Preservation of the functional cortex without corticosteroids was achieved in 5 (83%) of out 6 cases with a follow-up of 26.2 ± 6 months. Today, these 5 patients have a preserved adrenal function without hormone replacement. CONCLUSIONS: Cortical-sparing adrenalectomy by the retroperitoneal endoscopic approach, in expert hands, is safe and feasible for the treatment of hereditary and sporadic pheochromocytoma in a context of low malignancy, making it possible to avoid the need for corticoid replacement in most cases

Functional adrenal cortex preservation: A good reason for posterior retroperitoneal endoscopic approach. / Preservación de corteza adrenal funcionante. Una buena razón para realizar un abordaje endoscópico retroperitoneal posterior.

INTRODUCTION: Cortical-sparing adrenalectomy is a suitable treatment for hereditary and sporadic bilateral pheochromocytoma, in cases of low risk of malignancy, to reduce the possibility of adrenal insufficiency assuming the chance of local recurrence. The aim of the study is to analyze the functional results of partial adrenalectomy by retroperitoneal endoscopic approach in single-adrenal patients or patients requiring bilateral adrenalectomy. METHODS: Prospective study between January 2015 and February 2016 including pheochromocytoma patients diagnosed with low risk of malignant mutations. All patients agreed to be included in the study. Experienced endocrine surgeons who have been trained in minimally invasive endocrine surgery performed the procedure using the same surgical technique. Demographic variables and clinical characteristics were collected, subsequently carrying out the descriptive analysis of the data. RESULTS: A total of 6 patients were registered, four associated with MEN type 2 syndrome and two in the context of VHL syndrome. Retroperitoneoscopic resection was performed without laparoscopic or open conversion and no postoperative complications; the average hospital stay was 2.5 days. Preservation of the functional cortex without corticosteroids was achieved in 5 (83%) of out 6 cases with a follow-up of 26.2 ± 6 months. Today, these 5 patients have a preserved adrenal function without hormone replacement. CONCLUSIONS: Cortical-sparing adrenalectomy by the retroperitoneal endoscopic approach, in expert hands, is safe and feasible for the treatment of hereditary and sporadic pheochromocytoma in a context of low malignancy, making it possible to avoid the need for corticoid replacement in most cases.

Heparin but not tissue plasminogen activator improves outcomes in donation after circulatory death liver transplantation in a porcine model.

Ischemic-type biliary lesions (ITBLs) arise most frequently after donation after circulatory death (DCD) liver transplantation and result in high morbidity and graft loss. Many DCD grafts are discarded out of fear for this complication. In theory, microvascular thrombi deposited during donor warm ischemia might be implicated in ITBL pathogenesis. Herein, we aim to evaluate the effects of the administration of either heparin or the fibrinolytic drug tissue plasminogen activator (TPA) as means to improve DCD liver graft quality and potentially avoid ITBL. Donor pigs were subjected to 1 hour of cardiac arrest (CA) and divided among 3 groups: no pre-arrest heparinization nor TPA during postmortem regional perfusion; no pre-arrest heparinization but TPA given during regional perfusion; and pre-arrest heparinization but no TPA during regional perfusion. In liver tissue sampled 1 hour after CA, fibrin deposition was not detected, even when heparin was not given prior to arrest. Although it was not useful to prevent microvascular clot formation, pre-arrest heparin did offer cytoprotective effects during CA and beyond, reflected in improved flows during regional perfusion and better biochemical, functional, and histological parameters during posttransplantation follow-up. In conclusion, this study demonstrates the lack of impact of TPA use in porcine DCD liver transplantation and adds to the controversy over whether the use of TPA in human DCD liver transplantation really offers any protective effect. On the other hand, when it is administered prior to CA, heparin does offer anti-inflammatory and other cytoprotective effects that help improve DCD liver graft quality. Liver Transplantation 24 665-676 2018 AASLD.

Reduced IL-6 levels and tumor-associated phospho-STAT3 are associated with reduced tumor development in a mouse model of lung cancer chemoprevention with myo-inositol.

Several promising chemopreventive agents have for lung cancer emerged in preclinical models and in retrospective trials. These agents have been shown to modulate pathways altered in carcinogenesis and reduce markers of carcinogenesis in animal and cell culture models. Cancer-prone transgenic mice with oncogenic Kras expressed in the airway epithelium (CcspCre/+ ; KrasLSL-G12D/+ ) were raised on diets compounded with myo-inositol. These animals form lung premalignant lesions in a stereotypical fashion over the ten weeks following weaning. Mice raised on myo-inositol containing diets showed potent reduction in the number, size, and stage of lesions as compared to those raised on control diets. myo-inositol has previously been reported to inhibit phosphoinositide 3-kinase (PI3K) signaling. However, in mice raised on myo-inositol, total PI3K signaling was largely unaffected. Proteomic and cytokine analyses revealed large reduction in IL-6 related pathways, including STAT3 phosphorylation. This effect was not due to direct inhibition of IL-6 production and autocrine signaling within the tumor cell, but rather through alteration in macrophage recruitment and in phenotype switching, with an increase in antitumoral M1 macrophages.

Role of CPS1 in Cell Growth, Metabolism and Prognosis in LKB1-Inactivated Lung Adenocarcinoma.

Background: Liver kinase B1 ( LKB1 ) is a tumor suppressor in lung adenocarcinoma (LADC). We investigated the proteomic profiles of 45 LADC cell lines with and without LKB1 inactivation. Carbamoyl phosphate synthetase 1 (CPS1), the first rate-limiting mitochondrial enzyme in the urea cycle, was distinctively overexpressed in LKB1-inactivated LADC cell lines. We therefore assessed the role of CPS1 and its clinical relevance in LKB1-inactivated LADC. Methods: Mass spectrometric profiling of proteome and metabolome and function of CPS1 were analyzed in LADC cell lines. CPS1 and LKB1 expression in tumors from 305 LADC and 160 lung squamous cell carcinoma patients was evaluated by immunohistochemistry. Kaplan-Meier and Cox regression analyses were applied to assess the association between overall survival and CPS1 and LKB1 expression. All statistical tests were two-sided. Results: CPS1 knockdown reduced cell growth, decreased metabolite levels associated with nucleic acid biosynthesis pathway, and contributed an additive effect when combined with gemcitabine, pemetrexed, or CHK1 inhibitor AZD7762. Tissue microarray analysis revealed that CPS1 was expressed in 65.7% of LKB1-negative LADC, and only 5.0% of LKB1-positive LADC. CPS1 expression showed statistically significant association with poor overall survival in LADC (hazard ratio = 3.03, 95% confidence interval = 1.74 to 5.25, P < .001). Conclusions: Our findings suggest functional relevance of CPS1 in LKB1-inactivated LADC and association with worse outcome of LADC. CPS1 is a promising therapeutic target in combination with other chemotherapy agents, as well as a prognostic biomarker, enabling a personalized approach to treatment of LADC.

CDDO-Me protects normal lung and breast epithelial cells but not cancer cells from radiation.

Although radiation therapy is commonly used for treatment for many human diseases including cancer, ionizing radiation produces reactive oxygen species that can damage both cancer and healthy cells. Synthetic triterpenoids, including CDDO-Me, act as anti-inflammatory and antioxidant modulators primarily by inducing the transcription factor Nrf2 to activate downstream genes containing antioxidant response elements (AREs). In the present series of experiments, we determined if CDDO-Me can be used as a radioprotector in normal non-cancerous human lung and breast epithelial cells, in comparison to lung and breast cancer cell lines. A panel of normal non-cancerous, partially cancer progressed, and cancer cell lines from both lung and breast tissue was exposed to gamma radiation with and without pre-treatment with CDDO-Me. CDDO-Me was an effective radioprotector when given ∼18 hours before radiation in epithelial cells (average dose modifying factor (DMF) = 1.3), and Nrf2 function was necessary for CDDO-Me to exert these radioprotective effects. CDDO-Me did not protect cancer lines tested from radiation-induced cytotoxicity, nor did it protect experimentally transformed human bronchial epithelial cells (HBECs) with progressive oncogenic manipulations. CDDO-Me also protected human lymphocytes against radiation-induced DNA damage. A therapeutic window exists in which CDDO-Me protects normal cells from radiation by activating the Nrf2 pathway, but does not protect experimentally transformed or cancer cell lines. This suggests that use of this oral available, non-toxic class of drug can protect non-cancerous healthy cells during radiotherapy, resulting in better outcomes and less toxicity for patients.

Proteomic signatures associated with p53 mutational status in lung adenocarcinoma.

p53 is commonly mutated in lung adenocarcinoma. Mutant p53 loses wild-type function and some missense mutations further acquire oncogenic functions, while p53 wild-type may also induce pro-survival signaling. Therefore identification of signatures based on p53 mutational status has relevance to our understanding of p53 signaling pathways in cancer and identification of new therapeutic targets. To this end, we compared proteomic profiles of three cellular compartments (whole-cell extract, cell surface, and media) from 28 human lung adenocarcinoma cell lines that differ based on p53 mutational status. In total, 11,598, 11,569, and 9090 protein forms were identified in whole-cell extract, cell surface, and media, respectively. Bioinformatic analysis revealed that representative pathways associated with epithelial adhesion, immune and stromal cells, and mitochondrial function were highly significant in p53 missense mutations, p53 loss and wild-type p53 cell lines, respectively. Of note, mRNA levels of peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC1-α), a transcription coactivator that promotes mitochondrial oxidative phosphorylation and mitochondrial biogenesis, was substantially higher in p53 wild-type cell lines compared to either cell lines with p53 loss or with missense mutation. Small interfering RNA targeting PGC1-α inhibited cell proliferation in p53 wild-type cell lines, indicative of PGC1-α and its downstream molecules as potential therapeutic targets in p53 wild-type lung adenocarcinoma.

Branching morphogenesis of immortalized human bronchial epithelial cells in three-dimensional culture.

While mouse models have contributed in our understanding of lung development, repair and regeneration, inherent differences between the murine and human airways requires the development of new models using human airway epithelial cells. In this study, we describe a three-dimensional model system using human bronchial epithelial cells (HBECs) cultured on reconstituted basement membrane. HBECs form complex budding and branching structures on reconstituted basement membrane when co-cultured with human lung fetal fibroblasts. These structures are reminiscent of the branching epithelia during lung development. The HBECs also retain markers indicative of epithelial cell types from both the central and distal airways suggesting their multipotent potential. In addition, we illustrate how the model can be utilized to understand respiratory diseases such as lung cancer. The 3D novel cell culture system recapitulates stromal-epithelial interactions in vitro that can be utilized to understand important aspects of lung development and diseases.

Radiation-enhanced lung cancer progression in a transgenic mouse model of lung cancer is predictive of outcomes in human lung and breast cancer.

PURPOSE: Carcinogenesis is an adaptive process between nascent tumor cells and their microenvironment, including the modification of inflammatory responses from antitumorigenic to protumorigenic. Radiation exposure can stimulate inflammatory responses that inhibit or promote carcinogenesis. The purpose of this study is to determine the impact of radiation exposure on lung cancer progression in vivo and assess the relevance of this knowledge to human carcinogenesis. EXPERIMENTAL DESIGN: K-ras(LA1) mice were irradiated with various doses and dose regimens and then monitored until death. Microarray analyses were performed using Illumina BeadChips on whole lung tissue 70 days after irradiation with a fractionated or acute dose of radiation and compared with age-matched unirradiated controls. Unique group classifiers were derived by comparative genomic analysis of three experimental cohorts. Survival analyses were performed using principal component analysis and k-means clustering on three lung adenocarcinoma, three breast adenocarcinoma, and two lung squamous carcinoma annotated microarray datasets. RESULTS: Radiation exposure accelerates lung cancer progression in the K-ras(LA1) lung cancer mouse model with dose fractionation being more permissive for cancer progression. A nonrandom inflammatory signature associated with this progression was elicited from whole lung tissue containing only benign lesions and predicts human lung and breast cancer patient survival across multiple datasets. Immunohistochemical analyses suggest that tumor cells drive predictive signature. CONCLUSIONS: These results demonstrate that radiation exposure can cooperate with benign lesions in a transgenic model of cancer by affecting inflammatory pathways, and that clinically relevant similarities exist between human lung and breast carcinogenesis.

Multipotent capacity of immortalized human bronchial epithelial cells.

While the adult murine lung utilizes multiple compartmentally restricted progenitor cells during homeostasis and repair, much less is known about the progenitor cells from the human lung. Translating the murine stem cell model to humans is hindered by anatomical differences between species. Here we show that human bronchial epithelial cells (HBECs) display characteristics of multipotent stem cells of the lung. These HBECs express markers indicative of several epithelial types of the adult lung when experimentally tested in cell culture. When cultured in three different three-dimensional (3D) systems, subtle changes in the microenvironment result in unique responses including the ability of HBECs to differentiate into multiple central and peripheral lung cell types. These new findings indicate that the adult human lung contains a multipotent progenitor cell whose differentiation potential is primarily dictated by the microenvironment. The HBEC system is not only important in understanding mechanisms for specific cell lineage differentiation, but also for examining changes that correlate with human lung diseases including lung cancer.

Irreparable complex DNA double-strand breaks induce chromosome breakage in organotypic three-dimensional human lung epithelial cell culture.

DNA damage and consequent mutations initiate the multistep carcinogenic process. Differentiated cells have a reduced capacity to repair DNA lesions, but the biological impact of unrepaired DNA lesions in differentiated lung epithelial cells is unclear. Here, we used a novel organotypic human lung three-dimensional (3D) model to investigate the biological significance of unrepaired DNA lesions in differentiated lung epithelial cells. We showed, consistent with existing notions that the kinetics of loss of simple double-strand breaks (DSBs) were significantly reduced in organotypic 3D culture compared to kinetics of repair in two-dimensional (2D) culture. Strikingly, we found that, unlike simple DSBs, a majority of complex DNA lesions were irreparable in organotypic 3D culture. Levels of expression of multiple DNA damage repair pathway genes were significantly reduced in the organotypic 3D culture compared with those in 2D culture providing molecular evidence for the defective DNA damage repair in organotypic culture. Further, when differentiated cells with unrepaired DNA lesions re-entered the cell cycle, they manifested a spectrum of gross-chromosomal aberrations in mitosis. Our data suggest that downregulation of multiple DNA repair pathway genes in differentiated cells renders them vulnerable to DSBs, promoting genome instability that may lead to carcinogenesis.

Immortalized epithelial cells derived from human colon biopsies express stem cell markers and differentiate in vitro.

BACKGROUND & AIMS: Long-term propagation of human colonic epithelial cells (HCEC) of adult origin has been a challenge; currently used HCEC lines are of malignant origin and/or contain multiple cytogenetic changes. We sought to immortalize human colon biopsy-derived cells expressing stem cell markers and retaining multilineage epithelial differentiation capability. METHODS: We isolated and cultured cells from biopsy samples of 2 patients undergoing routine screening colonoscopy. Cells were immortalized by expression of the nononcogenic proteins cyclin-dependent kinase 4 (Cdk4) and the catalytic component of human telomerase (hTERT) and maintained for more than 1 year in culture. RESULTS: The actively proliferating HCECs expressed the mesenchymal markers vimentin and alpha-smooth muscle actin. Upon growth arrest, cells assumed a cuboidal shape, decreased their mesenchymal features, and expressed markers of colonic epithelial cells such as cytokeratin 18, zonula occludens-1, mucins-1 and -2, antigen A33, and dipeptidyl peptidase 4. Immortalized cells expressed stem cell markers that included LGR5, BMI1, CD29, and CD44. When placed in Matrigel in the absence of a mesenchymal feeder layer, individual cells divided and formed self-organizing, cyst-like structures; a subset of cells exhibited mucin-2 or polarized villin staining. CONCLUSIONS: We established immortalized HCECs that are capable of self-renewal and multilineage differentiation. These cells should serve as valuable reagents for studying colon stem cell biology, differentiation, and pathogenesis.

The DNA sequence, annotation and analysis of human chromosome 3.

After the completion of a draft human genome sequence, the International Human Genome Sequencing Consortium has proceeded to finish and annotate each of the 24 chromosomes comprising the human genome. Here we describe the sequencing and analysis of human chromosome 3, one of the largest human chromosomes. Chromosome 3 comprises just four contigs, one of which currently represents the longest unbroken stretch of finished DNA sequence known so far. The chromosome is remarkable in having the lowest rate of segmental duplication in the genome. It also includes a chemokine receptor gene cluster as well as numerous loci involved in multiple human cancers such as the gene encoding FHIT, which contains the most common constitutive fragile site in the genome, FRA3B. Using genomic sequence from chimpanzee and rhesus macaque, we were able to characterize the breakpoints defining a large pericentric inversion that occurred some time after the split of Homininae from Ponginae, and propose an evolutionary history of the inversion.

The finished DNA sequence of human chromosome 12.

Human chromosome 12 contains more than 1,400 coding genes and 487 loci that have been directly implicated in human disease. The q arm of chromosome 12 contains one of the largest blocks of linkage disequilibrium found in the human genome. Here we present the finished sequence of human chromosome 12, which has been finished to high quality and spans approximately 132 megabases, representing approximately 4.5% of the human genome. Alignment of the human chromosome 12 sequence across vertebrates reveals the origin of individual segments in chicken, and a unique history of rearrangement through rodent and primate lineages. The rate of base substitutions in recent evolutionary history shows an overall slowing in hominids compared with primates and rodents.