[Clinicopathological and genetic characteristics of congenital cystic adenomatoid malformation of lung and its associated lung cancer in adults].

Objective: To investigate the clinicopathological features and genetic characteristics of congenital cystic adenomatoid malformation (CCAM) of lung and CCAM associated lung cancer in adults. Methods: A total of 13 cases of CCAM of lung in adults, diagnosed from June 2015 to May 2023, were collected from the Department of Pathology, Shanghai Pulmonary Hospital, Tongji University School of Medicine, China. Their histopathological features were correlated with probable development into lung cancer. Next-generation sequencing was performed on the benign and malignant areas of all cases. Results: The pathological classification of all cases were of CCAM of lung type 1. There were 4 male and 9 female cases, age ranged from 18 to 65 years, with a mean age of 41 years. Six cases were accompanied by lung cancer, all of them were mucinous adenocarcinoma. Next-generation sequencing showed no gene mutation in 2 of the 13 cases; KRAS mutations in exon 2 were detected in 7 cases, in which there were 6 cases complicated with lung mucinous adenocarcinoma and no matter in the malignant or benign regions, the same case exhibited the same mutation sites in KRAS gene. Conclusions: CCAM of the lung is a congenital disease, and in adults, type 1 is most commonly found in the pathological classification, and it is often accompanied by cancer. Gene mutations are frequently detected in CCAM of the lung, KRAS being the most recurrent mutation which may play an important role in the carcinogenesis.

No Pathogenic DICER1 Gene Variants in a Cohort Study of 28 Children With Congenital Pulmonary Airway Malformation.

BACKGROUND: Distinguishing congenital pulmonary airway malformations (CPAMs) from pleuropulmonary blastoma (PPB) can be challenging. Previously diagnosed patients with CPAM may have been misdiagnosed and we may have missed DICER1-associated PPBs, a diagnosis with important clinical implications for patients and their families. To gain insight in potential misdiagnoses, we systematically assessed somatic DICER1 gene mutation status in an unselected, retrospective cohort of patients with a CPAM diagnosis. METHODS: In the Amsterdam University Medical Center (the Netherlands), it has been standard policy to resect CPAM lesions. We included all consecutive cases of children (age 0-18 years) with a diagnosis of CPAM between 2007 and 2017 at this center. Clinical and radiographic features were reviewed, and DICER1 gene sequencing was performed on DNA retrieved from CPAM tissue samples. RESULTS: Twenty-eight patients with a surgically removed CPAM were included. CPAM type 1 and type 2 were the most common subtypes (n = 12 and n = 13). For 21 patients a chest CT scan was available for reassessment by two pediatric radiologists. In 9 patients (9/21, 43%) the CPAM subtype scored by the radiologists did not correspond with the subtype given at pathology assessment. No pathogenic mutations and no copy number variations of the DICER1 gene were found in the DNA extracted from CPAM tissue (0/28). CONCLUSIONS: Our findings suggest that the initial CPAM diagnoses were correct. These findings should be validated through larger studies to draw conclusions regarding whether systematic DICER1 genetic testing is required in children with a pathological confirmed diagnosis of CPAM or not. LEVEL OF EVIDENCE: Level IV.

Congenital Pulmonary Airway Malformations With a Reconsideration and Current Perspective on the Stocker Classification.

Congenital cystic pulmonary lesions (CCPLs) are represented by the following entities: congenital pulmonary airway malformation (CPAM), formerly congenital cystic adenomatoid malformation, extra- and intralobar sequestration (EIS), congenital lobar emphysema (overexpansion), and bronchogenic cyst. The developmental model of CPAM histogenesis by Stocker proposed perturbations designated as CPAM type 0 to type 4 without known or specific pathogenetic mechanisms along the airway from the bronchus to the alveolus. This review highlights mutational events either at the somatic level in KRAS (CPAM types 1 and possibly 3) or germline variants in congenital acinar dysplasia, formerly CPAM type 0, and pleuropulmonary blastoma (PPB), type I, formerly CPAM type 4. The potential for overt malignant progression exists in the case of PPB type I and CPAM type 1 in some cases to well-differentiated mucinous adenocarcinoma. On the other hand, CPAM type 2 is an acquired lesion resulting from interruption in lung development secondary to bronchial atresia. The latter is also regarded as the etiology of EIS whose pathologic features are similar, if not identical, to CPAM type 2. These observations have provided important insights into the pathogenetic mechanisms in the development of the CPAMs since the Stocker classification.

Morphologic Features in Congenital Pulmonary Airway Malformations and Pulmonary Sequestrations Correlate With Mutation Status: A Mechanistic Approach to Classification.

Congenital pulmonary airway malformations (CPAMs) have a range of morphologies with varying cyst sizes and histologic features (types 1 to 3). Evidence suggested they arise secondary to bronchial atresia, however, we recently showed that cases with type 1 and 3 morphology are driven by mosaic KRAS mutations. We hypothesized that 2 distinct mechanisms account for most CPAMs: one subset is secondary to KRAS mosaicism and another is due to bronchial atresia. Cases with type 2 histology, similar to sequestrations, would be related to obstruction and therefore negative for KRAS mutations regardless of cyst size. We sequenced KRAS exon 2 in type 2 CPAMs, cystic intralobar and extralobar sequestrations, and intrapulmonary bronchogenic cysts. All were negative. Most sequestrations had a large airway in the subpleural parenchyma adjacent to the systemic vessel, anatomically confirming bronchial obstruction. We compared morphology to type 1 and 3 CPAMs. On average, type 1 CPAMs had significantly larger cysts, but there remained substantial size overlap between KRAS mutant and wild-type lesions. Features of mucostasis were frequent in sequestrations and type 2 CPAMs, while their cysts were generally simple and round with flat epithelium. Features of cyst architectural and epithelial complexity were more common in type 1 and 3 CPAMs, which rarely showed mucostasis. Similarity in histologic features among cases that are negative for KRAS mutation support the hypothesis that, like sequestrations, the malformation of type 2 CPAMs is related to obstruction during development. A mechanistic approach to classification may improve existing subjective morphologic methods.

Neonatal congenital pulmonary airway malformation associated with mucinous adenocarcinoma and KRAS mutations.

AIM OF THE STUDY: Congenital pulmonary airway malformation (CPAM) has an estimated prevalence in Europe of 1.06/10,000 live births with most being detected using maternal ultrasound screening. Malignant transformation is a possible complication though its prevalence is unknown and previous reports have usually been in older children. We reviewed our experience to identify those CPAM cases associated with malignancy. METHODS: Single centre retrospective review of all surgically treated children with antenatally-detected CPAM, with detailed review of cases associated with malignancy. MAIN RESULTS: 210 infants and children underwent resectional surgery for CPAM during the period 1994-2020, with 43(20.5%) undergoing surgery during the neonatal period. Of these, 3 infants, all males, had undergone surgical resection for respiratory distress (at 3, 4 and 8 days of life) with subsequent histological confirmation as Stocker type 1 CPAM with clear foci of mucinous adenocarcinoma. Subsequent genetic analysis showed somatic KRAS (Kirsten Rat Sarcoma Viral Oncogene) mutations in all three cases. No adjuvant treatment was required, and all are asymptomatic and disease-free at most recent follow-up (8 months, 2 and 6 years) CONCLUSIONS: This series highlights a clear association between type 1 CPAM and mucinous adenocarcinoma with KRAS point mutations, suggesting that the process of carcinogenesis has the potential to start in utero. This underlines the importance of discussing the risk of malignancy in prenatal and postnatal counselling.

Global interpretation of novel alternative splicing events in human congenital pulmonary airway malformations: A pilot study.

Little is known about differentially expressed genes (DEGs) and alternative splicing (AS) landscapes in congenital lung malformations (CLMs). We applied reference-based assembly of sequencing reads from RNA sequencing (RNA-seq) libraries to identify DEGs and AS landscapes in the lesions and normal lung tissue from the most common types of CLMs, including congenital pulmonary airway malformation-Ⅰ (CPAM-Ⅰ), CPAM-Ⅱ, intralobar sequestration (ILS), and ILS with CPAM (ILS-CPAM). We analyzed the expression profiles and related biological functions of AS events (ASEs). We further constructed a co-expression regulatory network between RNA binding protein (RBP) genes and corresponding ASEs to explore the related pathways in the regulated network. Ten DEGs were identified in the four types of CLMs, including eight upregulated genes and two downregulated genes. Additionally, 16 differential ASEs were detected, including the genes MACF1, RFX2, and FBXL4. Gene ontology (GO) enrichment was mainly observed in embryonic visual malformation and apoptotic process, and the KEGG pathway mainly enriched in the PI3K/AKT signaling pathway. We also detected 13 differentially expressed RBPs among 1979 DEGs in CPAM-I, in which ASEs in the MACF1 gene and RBP genes TLR8 and PTRH1 were closely associated. Moreover, we confirmed that the expression levels of PTRH1, NSUN7, and DZIP1L abundantly increased and the expression levels of TLR8, MEF2A, and NIPBL decreased in the CPAM-I lung tissue compared with the controls. It is suggested that ASEs in different types of CLMs is prominently different from normal controls, and ASEs differences occurring in CPAM-I malformation tissue are dramatically different from other types, which demonstrates the complex pathogenesis of CLMs and provides foundations for future studies to elucidate the mechanisms of developing CLMs.

Mucinous Adenocarcinoma With Intrapulmonary Metastasis Harboring KRAS and GNAS Mutations Arising in Congenital Pulmonary Airway Malformation.

OBJECTIVES: Mucinous adenocarcinoma arising in unresected congenital pulmonary airway malformation (CPAM) is rare. Underlying driver mutations in addition to KRAS gain-of-function mutations in this setting and the long-term outcomes of these patients are unknown. METHODS: We report a case of metastatic mucinous adenocarcinoma harboring both KRAS and GNAS mutations arising in a type 1 CPAM of a 14-year-old male. A literature review was performed. RESULTS: Next-generation sequencing revealed identical KRAS (G12V) mutations in both the CPAM and metastatic adenocarcinoma and a missense mutation in the GNAS (R201C) gene in the metastatic adenocarcinoma only. Median survival was 23 and 4 years for patients with localized (no or limited spread within the same lobe of CPAM) and distant involvement (spread to any different lobe of CPAM) of mucinous cells, respectively (95% confidence interval, 23-23 and 1.5-22 years, respectively; P = .017). CONCLUSIONS: Mucinous cell proliferation associated with type 1 CPAM has exceptionally good long-term outcomes if confined within the same lobe of CPAM. A second oncogenic mutation in the GNAS gene may be necessary for progression to malignancy and distant spread.

Prenatal diagnosis of submicroscopic chromosomal aberrations in fetuses with congenital cystic adenomatoid malformation by chromosomal microarray analysis.

OBJECTIVES: To explore the copy number variations (CNVs) of fetal congenital cystic adenomatoid malformation (CCAM). METHODS: Fetuses with CCAM were investigated by karyotypes and chromosomal microarray analysis (CMA). The cases were classified as isolated or CCAM with additional structural anomalies. The pregnancy outcome and neonatal prognosis were reported after the follow-up investigation. RESULTS: The karyotypes of 43 fetuses were analyzed and no abnormal karyotype was detected. Thirty-seven cases were further tested using CMA. The CMA identified pathogenic CNVs in three fetuses with a pathogenic detection rate of 8.1%. Well-known microdeletion or microduplication syndromes, including RCAD syndrome, HNPP, and CMT1A were identified, among which HNPP and CMT1A were incidental findings. After excluding two incidental findings, there were no pathogenic CNVs in isolated CCAM. There were no significant differences in pathogenic CNVs between isolated CCAM and CCAM with additional structural anomalies (0%, 0/31 versus 16.7%, 1/6, p=.162). Nearly half of the patients (53.8%, 14/26) underwent surgery after birth with good postoperative recoveries while the remaining half patients were spontaneous regression or asymptomatic. CONCLUSIONS: The results demonstrated the value of CMA in the prenatal diagnosis of CCAM. CCAM associated with other structural defects enhanced the frequency of pathogenic CNVs while isolated CCAM may not be associated with an increase in the prevalence of pathogenic CNVs. CCAMs have an overall good prognosis.

Mucinous adenocarcinoma arising in congenital pulmonary airway malformation: clinicopathological analysis of 37 cases.

AIMS: Mucinous adenocarcinoma arising in congenital pulmonary airway malformation (CPAM) is a rare complication, with little being known about its natural course. The aims of this article are to describe a series of mucinous adenocarcinomas arising from CPAMs, and present their clinicopathological features, genetics, and clinical outcome. METHODS AND RESULTS: Thirty-seven cases were collected within a 34-year period, and the subtype of adenocarcinoma and CPAM, tumour location, stage, growth patterns, molecular data and follow-up were recorded. The cohort comprised CPAM type 1 (n = 33) and CPAM type 2 (n = 4). Morphologically, 34 cases were mucinous adenocarcinomas (21 in situ; 13 invasive), and three were mixed mucinous and non-mucinous adenocarcinoma. Seventeen cases showed purely extracystic (intra-alveolar) adenocarcinoma, 15 were mixed intracystic and extracystic, and five showed purely intracystic proliferation. Genetically, nine of 10 cases tested positive for KRAS mutations, four with exon 2 G12V mutation and five with exon 2 G12D mutation. Residual disease on completion lobectomy was observed in two cases, and three cases recurred 7, 15 and 32 years after the original diagnosis. Two patients died of metastatic invasive mucinous adenocarcinoma. CONCLUSIONS: Most adenocarcinoma that arise in type 1 CPAMs, are purely mucinous, and are early-stage disease. Intracystic proliferation is associated with lepidic growth, an absence of invasion, and indolent behaviour, whereas extracystic proliferation may be associated with more aggressive behaviour and advanced stage. Most cases are cured by lobectomy, and recurrence/residual disease seems to be associated with limited surgery. Long-term follow-up is needed, as recurrence can occur decades later.

Single-cell transcriptome profiling reveals the mechanism of abnormal proliferation of epithelial cells in congenital cystic adenomatoid malformation.

OBJECTIVES: Congenital cystic adenomatoid malformation (CCAM) is the most common congenital pulmonary anomaly with unknown etiology. Here, single-cell RNA sequencing (scRNA-seq) was used to map its cellular landscape and identify the underlying cellular and molecular events related to CCAM. METHODS: This study involved a 4.25 year old patient with grade Ⅱ-Ⅲ CCAM at the Children's Hospital of Fudan University. Samples of lesioned and non-lesioned areas were collected during surgery for scRNA-seq. RESULTS: In total, 19,904 cells were obtained with median UMI counts of 7032 per cell and 1995 median genes per cell. In terms of lesioned and non-lesioned areas, epithelial cells accounted for 27.23% and 17.85%, respectively, while mesenchymal cells accounted for 2.67% and 16.06%, respectively (P < 0.0001). Further clustering of epithelial cells revealed that the fractions of alveolar type 1 cells (AT1, N: 23.65%; L: 49.81%), AT2(N: 2.02%; L: 5.26%), club-1(N: 9.02%; L: 17.57%), club-3(N: 1.18%; L: 4.15%), and basal cells (N: 0.34%; L: 2.93%) were increased in lesioned samples (P < 0.0001). Pseudotime trajectory analysis showed tracks of club-1/basal cells→AT2→club-3→AT1 and club-1,2/basal→AT2. Mast cells (N: 0.63%; L: 2.48%) were also increased in lesioned samples and interactions of CD44 with HBEGF and FGFR2 were detected between mast and epithelial cells. CONCLUSIONS: AT1, AT2, club, and basal cells were increased in CCAM patients, and newly defined club-1/3 and basal cells might be the origin of proliferating AT1 and AT2 cells. Increased mast cells might promote epithelial cell proliferation through interactions of CD44 with HBEGF and FGFR2.

Early KRAS oncogenic driver mutations in nonmucinous tissue of congenital pulmonary airway malformations as an indicator of potential malignant behavior.

The potential for malignant degeneration is the most common reason for some practitioners to resect asymptomatic congenital pulmonary airway malformations (CPAMs). We aimed to investigate the potential of various immunohistochemical (IHC) and genomic biomarkers to predict the presence of mucinous proliferations (MPs) in CPAM. Archival CPAM tissue samples were re-assessed and underwent IHC analysis using a panel of differentiating markers (TTF1/CDX2/CC10/MUC2/MUC5AC/p16/p53/DICER1). In each sample, intensity of IHC staining was assessed separately in normal lung tissue, CPAM, and MP tissue, using a semiquantitative approach. Likewise, next-generation targeted sequencing of known adult lung driver mutations, including KRAS/BRAF/EGFR/ERBB2, was performed in all samples with MP and in control samples of CPAM tissue without MP. We analyzed samples of 25 CPAM type 1 and 25 CPAM type 2 and found MPs in 11 samples. They were all characterized by strong MUC5AC expression, and all carried a KRAS mutation in the MP and adjacent nonmucinous CPAM tissue, whereas the surrounding normal lung tissue was negative. By contrast, in less than half (5 out of 12) control samples lacking MP, the CPAM tissue also carried a KRAS mutation. KRAS mutations in nonmucinous CPAM tissue may identify lesions with a potential for malignant degeneration and may guide histopathological assessment and patient follow-up.

A case report of an unusual non-mucinous papillary variant of CPAM type 1 with KRAS mutations.

BACKGROUND: congenital pulmonary airway malformation (CPAM) is the most frequent congenital lung disorder. CPAM type 1 is the most common subtype, typically having a cystic radiological and histological appearance. Mucinous clusters in CPAM type 1 have been identified as premalignant precursors for mucinous adenocarcinoma. These mucinous adenocarcinomas and the mucinous clusters in CPAM commonly harbor a specific KRAS mutation. CASE PRESENTATION: we present a case of a 6-weeks-old girl with CPAM type 1 where evaluation after lobectomy revealed a highly unusual complex non-mucinous papillary architecture in all cystic parts, in which both mucinous clusters and non-mucinous papillary areas harbored the known KRAS mutation. CONCLUSIONS: we found that a KRAS mutation thought to be premalignant in mucinous clusters only, was also present in the other cyst lining epithelial cells of this unusual non-mucinous papillary variant of CPAM type 1, warranting clinical follow-up because of uncertain malignant potential.

Congenital cystic adenomatoid malformations of the lung: an epithelial transcriptomic approach.

BACKGROUND: The pathophysiology of congenital cystic adenomatoid malformations (CCAM) of the lung remains poorly understood. AIM: This study aimed to identify more precisely the molecular mechanisms limited to a compartment of lung tissue, through a transcriptomic analysis of the epithelium of macrocystic forms. METHODS: Tissue fragments displaying CCAM were obtained during planned surgical resections. Epithelial mRNA was obtained from cystic and normal areas after laser capture microdissection (LCM). Transcriptomic analyses were performed and the results were confirmed by RT-PCR and immunohistochemistry in independent samples. RESULTS: After controlling for RNA quality, we analysed the transcriptomes of six cystic areas and five control areas. In total, 393 transcripts were differentially expressed in the epithelium, between CCAM and control areas. The most highly redundant genes involved in biological functions and signalling pathways differentially expressed between CCAM and control epithelium included TGFB2, TGFBR1, and MAP 2 K1. These genes were considered particularly relevant as they have been implicated in branching morphogenesis. RT-qPCR analysis confirmed in independent samples that TGFBR1 was more strongly expressed in CCAM than in control tissues (p < 0.03). Immunohistochemistry analysis showed TGFBR1 (p = 0.0007) and TGFB2 (p < 0.02) levels to be significantly higher in the epithelium of CCAM than in that of control tissues. CONCLUSIONS: This compartmentalised transcriptomic analysis of the epithelium of macrocystic lung malformations identified a dysregulation of TGFB signalling at the mRNA and protein levels, suggesting a possible role of this pathway in CCAM pathogenesis. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT01732185.

Analysis of Wnt7B and BMP4 expression patterns in congenital pulmonary airway malformation.

BACKGROUND: Congenital pulmonary airway malformation (CPAM) is a rare disorder characterized by aberrant overgrowth of terminal bronchioles. The objective of this study was to describe wingless-type MMTV integration site family 7B (Wnt7B) and bone morphogenetic protein 4 (BMP4) expression patterns in human CPAM lesions and to explore the possible roles of Wnt7B and BMP4 in the pathogenesis of CPAM. METHODS: Fifteen tissue samples from patients with CPAM were obtained from the Pathology Department of Shengjing Hospital of China Medical University. Samples representing CPAM lesions and adjacent normal lung tissues were collected and Wnt7B and BMP4 expression was detected through immunohistochemical (IHC) staining, quantitative real-time polymerase chain reaction (qRT-PCR), and Western blotting. RESULTS: IHC revealed that Wnt7B immunopositive cells were only detected in epithelial cells, whereas BMP4 immunopositive cells were detected in epithelial and mesenchymal cells. Expression of Wnt7B and BMP4 immunopositive cells was higher in CPAM lesions than that in adjacent normal lung tissue. qRT-PCR and Western blotting showed that Wnt7B and BMP4 mRNA and protein expression were significantly higher in CPAM lesions than in adjacent normal lung tissue (P < .05). Overall, the level of BMP4 was higher than that of Wnt7B. CONCLUSIONS: Increased expression of Wnt7B and BMP4 appear to be related to the pathogenesis of CPAM and abnormal pulmonary development. Upregulation of Wnt7B and BMP4 could play an important role in the development of the bronchial-alveolar structures that characterize CPAM.

Utilidad de la quimioterapia con corticoides en la reducción de volumen de las lesiones en fetos con malformación congénita de la vía aérea pulmonar (MCVAP): serie de casos / Usefulness of chemotherapy with corticosteroids in reducing the volume of the lesions in fetuses with congenital pulmonary airway malformation (MCVAP): case series

RESUMEN OBJETIVO: el propósito es describir el efecto de los corticoides prenatales en la malformación congénita de la vía aérea pulmonar (MCVAP) mediante la evaluación secuencial del CVR y mostrar la experiencia en nuestro centro de terapia fetal. MATERIALES Y MÉTODOS: serie de casos en la cual se incluyeron ocho pacientes del Hospital de San José; con diagnóstico de MCVAP; se evaluó edad gestacional, el CVR (longitud x largo x ancho, en cms de la masa) x 0.523/circunferencia cefálica) como factor pronóstico, la desviación mediastínica, la presencia de hidrops, el tipo de MCVAP y la localización. Se aplicó betametasona a dosis de inducción de madurez pulmonar fetal. Se realizó la medición del CVR pre y pos tratamiento. Los datos obtenidos fueron analizados mediante el software estadístico SPSS (Versión 11.0 SPSS Inc. Chicago, IL). Se utilizaron la prueba Wilcoxon y el índice de correlación de Spearman según el caso. Un valor de p<0.05 se consideró significativo. RESULTADOS: ocho pacientes fueron incluidas. La mediana de la edad gestacional fue 30.5 semanas. Cuatro casos fueron tipo I, dos tipo II y dos tipo tres. Cuatro casos presentaron desviación mediastinal. Cinco casos fueron derechos y uno bilateral. Ningún caso presentó hidrops. El CVR pre tratamiento fue 0,93(RIQ:0,17-2,1) y pos tratamiento 0,55(RIQ:0,07-1,39). Se encontró una disminución del CVR pos tratamiento en todos los casos (p 0.0117) e índice de correlación de Spearman 0.9524 CONCLUSIÓN: Después de la aplicación de corticoides encontramos una disminución del CVR en todos los casos descritos. El uso de corticoides podría ser parte de la terapia prenatal con miras a mejorar el pronóstico.

ABSTRACT OBJECTIVE: The purpose of this study is to describe the effect of prenatal corticosteroids in the CPAM by sequential evaluation of the CVR, and to show the experience in our fetal therapy center. MATERIALS AND METHODS: Series of cases in which eight patients from the Hospital of San José were included; with diagnosis of CPAM; gestational age was evaluated, CVR (CVR = length x length x width cm, mass) x 0.523 / head circumference) as a prognostic factor, mediastinal shift, hydrops, type of CPAM, location. Betamethasone was applied to fetal lung maturation dose. In all patients underwent CVR measurement pre and post treatment. The data were analyzed using SPSS statistical software (Version 11.0 SPSS Inc. Chicago, IL). The Wilcoxon test and the Spearman correlation index were used according to the case. A value of p <0.05 was considered significant. RESULTS: eight patients were included. The median of gestational age was 30.5 weeks. Four cases were type I, two type II and two type three. Four cases were mediastinal shift. Five cases were rights and one bilateral. No case presented hydrops. The pretreatment CVR was 0,93(RIQ: 0,17-2,1) and post-treatment 0,55(RIQ: 0,07-1,39). We found a decrease in CVR after treatment in all cases (p 0.0117) and Spearman correlation index 0.9524 CONCLUSION: After application of corticosteroids are a reduction in CVR in all the cases described. The use of corticosteroids may be part of prenatal therapy to improve prognosis.

Gene expression profiling reveals differential patterns between microcystic congenital cystic adenomatoid malformation and congenital lobar emphysema.

INTRODUCTION: Congenital cystic adenomatoid malformation (CCAM), especially type-III, shares similar sonographic features with congenital lobar emphysema (CLE) in routine ultrasound scan. Thus, prenatal differentiation of CLE from a microcystic CCAM is challenging and difficult in practice. Discovery of molecular biomarkers has important clinical significance. METHODS: We profiled gene expression in lung tissue from four CCAM type-III and five CLE subjects by microarray. A bioinformatic tool was used for signal pathways enrichment analysis. Further, quantitative reverse transcriptase PCR (qRT-PCR) was used to verify the results. RESULTS: A total of 426 genes were identified to be significantly differentially expressed (fold-change >2.0, q value <0.05) between microcystic CCAM and CLE. Of these differentially expressed genes (DEGs), 392 were upregulated and 34 were downregulated in microcystic CCAM compared with CLE. Unsupervised clustering of the "expressed" genes could clearly delineate the CCAM and CLE samples. We also confirmed that eight randomly chose genes were differentially expressed at the mRNA level between CCAM and CLE. CONCLUSIONS: CCAM type-III and CLE have differential gene expression patterns. Our pilot study may gain a deeper understanding of the organogenetic origins and pathogenesis of these conditions. The suggestive candidates may serve as potential biomarkers for definitive diagnosis of congenital cystic lung lesions and eventually to treat them appropriately.

Elevated Krüppel-like factor 5 expression in spatiotemporal mouse lungs is similar to human congenital cystic adenomatoid malformation of the lungs.

Objective The study aimed to investigate the role of high Krüppel-like factor 5 (KLF5) expression on the pathogenesis of congenital cystic adenomatoid malformation of the lungs (CCAML) in mice. Methods A mouse model of high KLF5 expression in the lungs was established. KLF5 expression and the pulmonary lumen diameter were examined by immunohistochemistry to determine a successful model. Basement membrane damage and activity of matrix metalloproteinase-9 (MMP-9) were examined. After an adenovirus carrying KLF5 gene transfection in lung adenocarcinoma (H441) was created, changes in expression and activity of MMP-9 were determined. Results In a mouse model with high KLF5 expression, the pulmonary lumen was markedly enlarged, indicating establishment of CCAML. The basement membrane was degraded, and MMP-9 activity was significantly higher in the model group compared with the control group. Moreover, mice in a cellular model after transfection also showed higher MMP-9 activity than did controls. Conclusion High KLF5 expression may play a pivotal role in the pathogenesis of CCAML, partly through regulating the activity of MMP-9.

Novel Molecular and Phenotypic Insights into Congenital Lung Malformations.

RATIONALE: Disruption of normal pulmonary development is a leading cause of morbidity and mortality in infants. Congenital lung malformations are a unique model to study the molecular pathogenesis of isolated structural birth defects, as they are often surgically resected. OBJECTIVES: To provide insight into the molecular pathogenesis of congenital lung malformations through analysis of cell-type and gene expression changes in these lesions. METHODS: Clinical data, and lung tissue for DNA, RNA, and histology, were obtained from 58 infants undergoing surgical resection of a congenital lung lesion. Transcriptome-wide gene expression analysis was performed on paired affected and unaffected samples from a subset of infants (n = 14). A three-dimensional organoid culture model was used to assess isolated congenital lung malformation epithelium (n = 3). MEASUREMENTS AND MAIN RESULTS: Congenital lung lesions express higher levels of airway epithelial related genes, and dysregulated expression of genes related to the Ras and PI3K-AKT-mTOR (phosphatidylinositol 3-kinase-AKT-mammalian target of rapamycin) signaling pathways. Immunofluorescence confirmed differentiated airway epithelial cell types throughout all major subtypes of congenital lung lesions, and three-dimensional cell culture demonstrated a cell-autonomous defect in the epithelium of these lesions. CONCLUSIONS: This study provides the first comprehensive analysis of the congenital lung malformation transcriptome and suggests that disruptions in Ras or PI3K-AKT-mTOR signaling may contribute to the pathology through an epithelial cell-autonomous defect.