Metagenomic analysis of oral plaques and aortic valve tissues reveals oral bacteria associated with aortic stenosis

OBJECTIVES

Bacteria derived from the oral cavity enter the bloodstream and cause the onset of various systemic diseases, including heart valve disease. However, information on the oral bacteria involved in aortic stenosis is limited.

MATERIALS AND METHODS

We comprehensively analyzed the microbiota in aortic valve tissues collected from aortic stenosis patients using metagenomic sequencing and investigated the relationships between the valve microbiota, the oral microbiota, and oral cavity conditions.

RESULTS

Metagenomic analysis revealed the presence of 629 bacterial species in five oral plaques and 15 aortic valve clinical specimens. Patients were classified into two groups (A and B) according to their aortic valve microbiota composition using principal coordinate analysis. Examination of the oral conditions of the patients showed no difference in the decayed/missing/filled teeth index. Bacteria in group B tend to be associated with severe disease, and the number of bacteria on the dorsum of the tongue and the positive rate of bleeding during probing were significantly higher in this group than in group A. The pathophysiology of aortic stenosis may be related to the presence of oral bacteria such as Streptococcus oralis and Streptococcus sanguinis following bacteremia.

CONCLUSIONS

Systemic inflammation in severe periodontitis may be driven by the oral microbiota, supporting the indirect (inflammatory) association between oral bacteria and aortic stenosis.

CLINICAL RELEVANCE

Appropriate oral hygiene management may contribute to the prevention and treatment of aortic stenosis.

[Retracted] Proteasome inhibitor sensitizes oral squamous cell carcinoma cells to TRAIL‑mediated apoptosis

Following the publication of this paper, it was drawn to the Editor's attention by a concerned reader that, in Fig. 4 on p. 650, the same β‑actin bands had apparently been used to show the experimental effects of the proteasome inhibitor MG‑132 on c‑FLIP in HSC‑2 cells in Fig. 4A, and the effects of MG‑132 on IAPs in HSC‑3 cells in Fig. 4B. In addition, for the fourth lane in the gel showing the effects of MG‑132 on c‑FLIP in HSC‑3 cells, this should have been labelled as '+MG‑132 / +TRAIL' (not as '‑/‑'). Upon contacting the authors in relation to this matter, they could only admit that errors had been made in the preparation of the figure; moreover, they no longer had access to the original data owing to the time that has elapsed since the publication of the paper, and it would be impossible for them to now repeat this experiment. After having considered this matter and in conjunction with a request made by the authors, the Editor of Oncology Reports has decided that this paper should be retracted from the publication. Both the Editor and the authors apologize to the readership for any inconvenience caused. [Oncology Reports 25: 645‑652, 2011; DOI: 10.3892/or.2010.1127].

Metastasis of Mammary Gland Malignant Phyllodes Tumor to the Mandibular Region: A Case Report and Review of the Literature

Phyllodes tumor is a rare breast tumor described by Müller (1938) as a lesion comprising leaflike stromal fibrous components and narrow cysts. The frequency of distant metastasis from this entity is reportedly approximately 20%, and no effective therapy has been established, so the prognosis is poor. This report describes the case of a 60-year-old woman with a history of left lung resection who showed metastasis of a mammary gland malignant phyllodes tumor to the oral cavity. Intraoral examination showed an elastic, hard mass measuring 28 × 27 mm in the gingiva around the left mandibular second molar. Biopsy examination showed growth of giant cells and roughly circular cells showing positivity for S-100, p63, and vimentin on immunohistochemical staining. The authors diagnosed metastasis of the mammary gland malignant phyllodes tumor to the left mandible and performed cyber knife irradiation (44 Gy in 5 fractions) of the left mandible. The mass in the oral cavity disappeared after cyber knife irradiation, but the patient died of direct invasion to the spine.

Aberrant expression of EZH2 is associated with pathological findings and P53 alteration

AIM

Enhancer of zeste homolog-2 (EZH2) and B lymphoma Mo-MLV insertion region-1 homolog (BMI1) are members of the polycomb group of proteins, which function as transcriptional repressors through chromatin modification. EZH2 forms part of the polycomb repressive complex (PRC)-2, while BMI1 is a component of PRC1. Previous studies have shown that EZH2 is highly expressed in various type of cancers. Expression of EZH2 is reported to be regulated by the P53-E2F/retinoblastoma (RB)-related pathway, and a correlation between P53 mutation and EZH2 expression was recently found in breast cancer. Here, we examined the relationship between P53 and EZH2 in oral squamous cell carcinoma (OSCC).

MATERIALS AND METHODS

Using immunohistochemistry, we investigated the expression of EZH2 and BMI1 in 99 surgically-resected OSCC and 34 epithelial dysplasia samples. We analyzed associations between aberrant expression of EZH2 and BMI1, and clinicopathological findings and patient outcome. P53 expression was also examined and analyzed in relation to EZH2 and BMI1 expression.

RESULTS

EZH2 and BMI1 protein were up-regulated in OSCC tissues compared with epithelial dysplasia and normal epithelium. Aberrant EZH2 and BMI1 protein expression was observed in 32 and 59 of the 99 OSCC samples, respectively. Aberrant EZH2 and BMI1 expression was significantly associated with mode of invasion, but not with lymph node metastasis or survival rate. Aberrant EZH2 expression was associated with P53 alteration in OSCC tissue. Expression of EZH2 mRNA in SAS/neo cells, which have wild-type P53, was significantly lower than in SAS/mp53 cells that have a mutant P53 gene.

CONCLUSION

P53 alteration may be involved in dysregulated EZH2 expression, and aberrant expression of EZH2 may play a role in carcinogenesis of OSCC.

Abstract 5000: Epigenomic profiling of oral cancer

Epigenetic aberration, such as dysregulation of DNA mathylation is often associated with human carcinogenesis. To analyze DNA methylation profiles of oral cancers, and to identify the methylation pattern specific to the clinicopathological features, we performed genome-wide methylation analysis using Infinium HumanMethylation27 BeadArray system. We found 2,361 aberrantly methylated CpG sites in 59 oral cancers compared to 3 normal mucosal tissues. By unsupervised clustering analysis, oral cancer was divided into two methylation epigenotypes that are significantly correlated with incidence of lymph node metastasis and differentiation grades. We selected the classifier genes that can predict tumor metastasis in the training set, and demonstrated that they are validated to be predictive in the independent test sample, preoperative biopsy samples. In summary, we identified two methylation epigenotypes correlated with clinical outcome in oral cancer, and candidate classifier genes that would be useful in patient stratification for intensive therapy to overcome the tumor recurrence.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5000. doi:1538-7445.AM2012-5000

Tissue-specific demethylation in CpG-poor promoters during cellular differentiation

Epigenetic regulation is essential in determining cellular phenotypes during differentiation. Although tissue-specific DNA methylation has been studied, the significance of methylation variance for tissue phenotypes remains unresolved, especially for CpG-poor promoters. Here, we comprehensively studied methylation levels of 27 578 CpG sites among 21 human normal tissues from 12 anatomically different regions using an epigenotyping beadarray system. Remarkable changes in tissue-specific DNA methylation were observed within CpG-poor promoters but not CpG-rich promoters. Of note, tissue-specific hypomethylation is accompanied by an increase in gene expression, which gives rise to specialized cellular functions. The hypomethylated regions were significantly enriched with recognition motifs for transcription factors that regulate cell-type-specific differentiation. To investigate the dynamics of hypomethylation events, we analyzed methylation levels of the entire APOA1 gene locus during in vitro differentiation of embryonic stem cells toward the hepatic lineage. A decrease in methylation was observed after day 13, coinciding with alpha-fetoprotein detection, in the vicinity of its transcription start sites (TSSs), and extends up to ∼200 bp region encompassing the TSS at day 21, equivalent to the hepatoblastic stage. This decrease is even more pronounced in the adult liver, where the entire APOA1 gene locus is hypomethylated. Furthermore, when we compared the methylation status of induced pluripotent stem (iPS) cells with their parental cell, IMR-90, we found that fibroblast-specific hypomethylation is restored to a fully methylated state in iPS cells after reprogramming. These results illuminate tissue-specific methylation dynamics in CpG-poor promoters and provide more comprehensive views on spatiotemporal gene regulation in terminal differentiation.

Proteasome inhibitor sensitizes oral squamous cell carcinoma cells to TRAIL-mediated apoptosis

Oral squamous cell carcinoma (OSCC) cells are relatively resistant to tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-mediated apoptosis during culture. We investigated the role of a proteaosome inhibitor in the survival and apoptosis of these cells. We found that the proteasome inhibitor MG132 markedly accelerated TRAIL-mediated apoptosis in OSCC cell lines HSC-2 and HSC-3. Addition of TRAIL to MG132-treated cells resulted in Bid cleavage. Furthermore, the inhibitors of caspase-3, caspase-8 and caspase-9 reduced the accelerative effect of MG132 on TRAIL-mediated apoptosis. These results suggest that the pro-apoptotic effect of a proteasome inhibitor on TRAIL-mediated apoptosis may contribute to both extrinsic and intrinsic pathways. MG132 enhanced the expression of the TRAIL receptors DR4 and DR5, and neutralization of DR5 receptors showed a marked reduction of TRAIL-mediated apoptosis, whereas that of DR4 was a partial reduction. MG132 also markedly reduced cellular FLICE-inhibitory protein (c-FLIP), cellular inhibitor of apoptosis protein-1 (cIAP-1), X-linked IAP (XIAP) and survivin. Therefore, MG132 provides partial regulation of TRAIL-mediated apoptosis in OSCC cells via modulation of DR5, c-FLIP, cIAP-1, XIAP and survivin. The proteasome inhibitor MG132 may therefore represent a novel strategy for overcoming resistance to TRAIL-mediated apoptosis in OSCC cells.

Antitumor activity of suberoylanilide hydroxamic acid against human oral squamous cell carcinoma cell lines in vitro and in vivo

It has been reported recently that histone deacetylase inhibitors (HDACIs) can block the growth of a variety of malignant tumor cells by reversing the silencing of the tumor suppressor genes; these will be the anticancer agents of the next generation. In this study, we evaluated the antitumor effects of the HDACI suberoylanilide hydroxamic acid (SAHA) on oral squamous cell carcinoma (OSCC) and investigated its molecular mechanism. SAHA suppressed the in vitro proliferation of OSCC cell lines in a dose- and time-dependent manner. Flow cytometric analyses showed that treatment with SAHA led to G1 phase cell-cycle arrest of OSCC cells, accompanying a decrease in the percentage of S-phase cells. Western blot analyses demonstrated that the expression of p21 protein was remarkably augmented and hyperacetylation of p53 was induced after SAHA treatment. These results suggest that administration of SAHA suppresses OSCC growth through G1 phase arrest. Additionally, we observed that the growth of xenograft SAS tumors in nude mice was significantly blocked by the administration of SAHA without major adverse effects.

Hypoxia induces resistance to 5-fluorouracil in oral cancer cells via G(1) phase cell cycle arrest

Malignant tumors are exposed to various levels of hypoxic condition in vivo. It has been known that tumor cells under hypoxia are resistant to chemotherapies. To clarify the mechanism of the hypoxia-induced chemoresistance, we evaluated the effects of hypoxia on the resistance of oral squamous cell carcinoma (OSCC) cell lines to 5-fluorouracil (5-FU). OSCC cells were divided to two groups by the proliferation activity under hypoxic condition; hypoxia-resistant (HR) and hypoxia-sensitive (HS) cells. Growth of HS cells were inhibited by hypoxia and introduced to G(1) arrest in cell cycle. 5-FU effect on HS cell viability was markedly reduced in hypoxic condition without an induction of chemoresistant related protein, P-glycoprotein. However, proliferation, cell cycle, and 5-FU sensitivity of HR cells were not affected by hypoxia. Hypoxia-inducible factor (HIF)-1alpha was induced by hypoxia in all OSCC cell lines, but diminished in HS cells within 48h. Expression of p21 and p27 was strongly augmented and CyclinD expression was reduced by hypoxia in HS cells. However, the expression of these proteins was constitutive in HR cells during 48h hypoxic culture. Phosphorylation of mammalian target of rapamycin (mTOR) was reduced by hypoxia in HS cells. From these findings, we concluded that HS OSCC cells acquire 5-FU resistance under hypoxia by G(1)/S transition through an upregulation of cell cycle inhibitors.

Epidermal growth factor receptor inhibitors enhance susceptibility to Fas-mediated apoptosis in oral squamous cell carcinoma cells

Molecular inhibition of epidermal growth factor receptor (EGFR) signaling is a promising cancer treatment strategy. We examined whether inhibition of EGFR signaling would affect the susceptibility of oral squamous cell carcinoma (OSCC) cells to Fas-mediated apoptosis. Treatment of OSCC cells with an anti-EGFR monoclonal antibody, C225, and an EGFR tyrosine kinase inhibitor, AG1478, which target the extracellular and intracellular domains of the receptor, respectively, inhibited phosphorylation of EGFR and its downstream effector molecule Akt and amplified the induction of Fas-mediated apoptosis. In OSCC cells treated with EGFR inhibitors, Fas-mediated apoptosis was accompanied by caspase-8 activation but not Bid cleavage. Caspase-3 and -8 inhibitors reduced the effect of EGFR inhibitors on Fas-mediated apoptosis in OSCC cells, but a caspase-9 inhibitor did not. These results indicate that the pro-apoptotic activity of EGFR inhibitors in OSCC cells depends on the extrinsic pathway of the caspase cascade. Although EGFR inhibitors did not affect the expression of Fas, the Fas-associated death domain protein, or procaspase-8 in OSCC cells, the inhibition downregulated cellular FLICE-inhibitory protein (c-FLIP). Moreover, knockdown of c-FLIP in HSC-2 cells with a small interfering RNA strongly enhanced Fas-mediated apoptosis. These results suggest that the EGFR signaling pathway may, in part, regulate Fas-mediated apoptosis in OSCC cells through c-FLIP expression.

Enhanced susceptibility to apoptosis of oral squamous cell carcinoma cells subjected to combined treatment with anticancer drugs and phosphatidylinositol 3-kinase inhibitors

The purpose of this study was to determine whether phosphatidylinositol 3-kinase (PI 3-K) inhibitors could modulate the apoptotic activity of the anticancer drugs cisplatin, 5-fluorouracil or docetaxel in an oral squamous cell carcinoma (OSCC) cell line, HSC-2. In preliminary experiments, cisplatin, 5-fluorouracil and docetaxel inhibited the proliferation of OSCC cells in a dose-dependent manner. We found that two PI 3-K inhibitors, wortmannin and LY294002, markedly suppressed the phosphorylation of Akt in OSCC cells. Treatment of OSCC cells with PI 3-K inhibitors significantly enhanced cisplatin-, 5-fluorouracil- or docetaxel-induced apoptosis. Caspase-3 and -9 inhibitors, but not a caspase-8 inhibitor, reduced anticancer drug-mediated apoptosis in PI 3-K inhibitor-treated OSCC cells, suggesting that the apoptotic pathway induced by the combination of anticancer drug therapy and PI 3-K inhibition may be functionally related to the intrinsic apoptotic pathway in OSCC cells. Expression of Bcl-2, cellular inhibitor of apoptosis protein-1 (cIAP-1), and X-linked IAP was down-regulated, and expression of Bax was up-regulated by PI 3-K inhibitors, while that of Bcl-xL, Bak and cIAP-2 was not attenuated. We also found that Bad phosphorylation was down-regulated by PI 3-K inhibitors. These results suggested that inhibition of PI 3-K enhances the susceptibility of OSCC cells to anticancer drug-mediated apoptosis through regulation of expression and post-translational modification of both pro- and anti-apoptotic proteins. These findings could potentially lead to new strategies for improving the efficacy of anticancer drugs in OSCC cells.

Effect of combining epidermal growth factor receptor inhibitors and cisplatin on proliferation and apoptosis of oral squamous cell carcinoma cells

Epidermal growth factor (EGF) is known to be involved in the proliferation and metastasis of squamous cell carcinoma (SCC), suggesting that the EGF receptor (EGFR) must also contribute to SCC development. In combination with conventional anti-cancer drugs, agents that block EGFR may represent an efficient means of inhibiting proliferation and inducing apoptosis in SCC cells. We investigated the effects of combining an anti-EGFR monoclonal antibody (C225) or an EGFR-selective tyrosine kinase inhibitor (AG1478) with the conventional anti-cancer drug cisplatin on the oral SCC (OSCC) cell lines NA and Ca9-22. We detected constitutive expression of EGFR on the cell membranes of both cell lines. OSCC cell proliferation was inhibited by C225, AG1478 and cisplatin in a dose-dependent manner. The combination of C225 or AG1478 with cisplatin at concentrations <IC50 synergistically inhibited cell proliferation and induced apoptosis in these cells. Furthermore, treatment with C225 or AG1478 OSCC reduced phosphorylation of EGFR and Akt, as well as Bad. EGFR inhibitors down-regulated expression levels of the anti-apoptotic proteins cellular IAP-1 (cIAP-1), X-linked IAP (XIAP), Bcl-2 and Bcl-xL, whereas those of the pro-apoptotic proteins Bax and Bak were up-regulated, and neither cIAP-2 nor survivin were affected. Therefore, EGFR inhibitors can provide partial regulation of cisplatin-mediated apoptosis in OSCC cells by modulating expression of cIAP-1, XIAP, Bcl-2, Bcl-xL, Bax and Bak. These results suggest that EGFR inhibitors may represent a novel strategy for overcoming resistance to cisplatin-mediated apoptosis via the phosphatidylinositol 3-kinase/Akt pathway.

Enhanced susceptibility to tumor necrosis factor-related apoptosis-inducing ligand-mediated apoptosis in oral squamous cell carcinoma cells treated with phosphatidylinositol 3-kinase inhibitors

In general, oral squamous cell carcinoma (OSCC) cells are relatively resistant to tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-mediated apoptosis during culture in vitro. Here, we studied the role of phosphatidylinositol 3-kinase (PI 3-K)/Akt in survival and apoptosis of these cells. The PI 3-K inhibitors wortmannin and LY294002 markedly suppressed phosphorylation of Akt and accelerated TRAIL-mediated apoptosis in OSCC cells. Addition of TRAIL to PI 3-K inhibitor-treated cells resulted in caspase-8 activation and loss of mitochondrial membrane potential. Furthermore, inhibitors of caspase-3, -8 and -9 reduced the accelerative effect of PI 3-K inhibitors on TRAIL-mediated apoptosis. These results suggest that the pro-apoptotic effect of PI 3-K inhibitors on TRAIL-mediated apoptosis may contribute to both the extrinsic and intrinsic pathways. Although PI 3-K inhibitors did not affect expression of the TRAIL receptors DR4 and DR5, we observed a marked reduction in expression of cellular FLICE-inhibitory protein (c-FLIP), Bcl-2, cellular inhibitor of apoptosis protein-1 (cIAP-1) and X-linked IAP (XIAP), whereas Bax was up-regulated and no significant difference was observed in expression of Bcl-xL, Bak or cIAP-2. Therefore, the PI 3-K/Akt signaling pathway provides partial regulation of TRAIL-mediated apoptosis in OSCC cells via modulation of c-FLIP, Bcl-2, Bax, cIAP-1 and XIAP expression. These results suggest that PI 3-K inhibitors may represent a novel strategy for overcoming resistance to TRAIL-mediated apoptosis in OSCC cells.

Impaired cardiorespiratory response to brief sudden strenuous exercise in the postoperative tetralogy of fallot patients: a ten-second pedaling test

No studies of cardiorespiratory response to brief, sudden, strenuous exercise in patients after tetralogy of Fallot (TOF) repair have been reported. We investigated the exercise capacity of TOF patients using a ten-second pedaling test designed to study cardiorespiratory responsiveness to brief, sudden, strenuous exercise. We assessed exercise capacity using a ten-second pedaling test (ten seconds maximal of voluntary cranking as fast as possible against an ergometer's inertial resistance), coupled with a conventional ramp-type progressive exercise test at a constant rate to the limit of tolerance, in eight male postoperative TOF patients and eight male control subjects. In the ten-second pedaling test, there were no significant differences in the integrated areas of heart rate (HR) and oxygen uptake () responses between the TOF patients and controls, but there were significantly longer decreasing phase time constants of HR and responses in the TOF patients than in the controls. In the conventional exercise test, the endurance time, peak-HR, and peak- did not differ between the groups. The TOF group, with a normal exercise capacity assessed by a conventional exercise test, had an impaired cardiorespiratory response to brief, sudden, strenuous exercise assessed by a ten-second pedaling test.

[Isoproterenol stress test for the evaluation of the residual stenosis of the right ventricular outflow tract]

Hemodynamic changes of the right side of the heart during isoproterenol stress test were assessed and analyzed in 36 patients who underwent definitive repair of tetralogy of Fallot or double outlet right ventricle with pulmonary stenosis. Patients having atresia of the pulmonary artery were excluded from the study. 24 of the patients had previously undergone reconstruction of the right ventricular outflow tract (RVOT) with preserving the pulmonary valvar annulus (group N), whilst the remaining 12 patients had undergone transannular enlargement of RVOT with a patch (group T). Preservation of the pulmonary valvar annulus was determined when the intra-operative measurement of diameter of the pulmonary valvar annulus showed values greater than 90% of normal. In both groups, the isoproterenol infusion increased the right to left ventricular peak pressure (RVP/LVP) ratio, pressure gradient between the right ventricle and main pulmonary artery (RV-mPAP), and pressure gradient between the main pulmonary artery and peripheral pulmonary artery (m-pPAP). These values were significantly higher than those measured at rest. When comparisons were made between groups, RV-mPAP of group N was significantly higher than that of group T, both at rest and during stress test. By contrast, m-pPAP of group T was significantly higher than that of group N, both at rest and during stress test. Although no significant difference was found between the groups in RVP/LVP at rest and during stress test, RVP/LVP of both groups increased to the level of more than 0.6 after the isoproterenol infusion. These results led us to conclude that preservation of the pulmonary valvar annulus was better to be applied only to the patients who fulfilled our criterions. Additionally, in the setting of patch reconstruction of the pulmonary artery, every effort should be made so as not to leave the residual stenosis of the peripheral pulmonary artery.

Ventricular septal defect associated with microdeletions of chromosome 22q11.2

Microdeletions of chromosome 22q11.2 (del.22q11) cause DiGeorge syndrome, velo-cardio-facial syndrome, and conotruncal anomaly face syndrome, which are commonly associated with conotruncal heart anomalies. Approximately 15% of the patients manifest ventricular septal defect (VSD), and the conal septal type of VSD has been proposed to be associated with del.22q11, since it is categorized as a conotruncal anomaly. However, the types of VSD associated with del.22q11 remain poorly studied. The purpose of this study is to assess whether conal septal VSD or other types of VSDs are associated with del.22q11. We analyzed the chromosomes of 22 consecutive patients with conal-septal VSD, prospectively, and evaluated the types of VSD observed in 3 patients with del.22q11, retrospectively. Del.22q11 was not detected in any of the 22 patients with conal septal VSD. All the VSDs observed in the 3 patients with del.22q11 were a perimembranous type of VSD, which is not a conotruncal anomaly. Our results suggest that perimembranous VSD can be associated with del.22q11, but del.22q11 is not a common cause of conal-septal VSD.

Frequent association of 22q11.2 deletion with tetralogy of Fallot

Chromosome 22q11.2 deletion causes DiGeorge syndrome, velocardiofacial syndrome, conotruncal anomaly face syndrome with tetralogy of Fallot (TOF), and sporadic or familial TOF. To determine the prevalence and clinical importance of the 22q11.2 deletion in TOF, a series of 212 Japanese TOF patients was studied. The type of pulmonary blood supply, which may lead to various clinical outcomes, and other additional anomalies were evaluated clinically. The 22q11.2 deletion was diagnosed by fluorescence in situ hybridization with N25 and TUPLE1 probes. Of the 212 patients examined, 28 (13%) had a 22q11.2 deletion, the frequency being higher than that in TOF patients with trisomy 21. The prevalence of the deletion in TOF patients with pulmonary atresia (PA) plus major aortico-pulmonary collateral arteries (MAPCA) was significantly higher than the value in patients with PA plus patent ductus arteriosus (PDA) (P = 0.04) or with pulmonary stenosis (PS) (P < 0.0001). All 28 patients with 22q11.2 deletion had one or more extracardiac abnormalities. Four of 9 patients with the 22q11.2 deletion and TOF-PA-MAPCA suffered from bronchomalacia, while none of 19 patients with TOF-PA-PDA or TOF-PS manifested bronchomalacia (P = 0.006). These results indicate that 22q11.2 deletion is the most frequent cause of syndromic TOF, especially for TOF-PA-MAPCA, and bronchomalacia is the clinically most important associated anomaly in TOF-PA-MAPCA patients.