[Prenatal diagnosis of fetal microdeletion and microduplication syndromes among pregnant women with advanced maternal ages].

OBJECTIVE: To assess the value of combined chromosomal karyotyping and chromosomal microarray analysis (CMA) and/or copy number variation sequencing (CNV-seq) for the prenatal diagnosis for women with advanced maternal ages, and to explore the challenges of prenatal genetic counseling brought by the types of fetal CNVs and uncertainty of related phenotypes. METHODS: A retrospective analysis was carried out on 1 841 women with advanced maternal age who underwent interventional prenatal diagnosis at the Prenatal Diagnosis Center of Xiamen University Affiliated Women and Children's Hospital from January 2017 to December 2020. Routine chromosomal karyotyping analysis and CMA/CNV-seq detection were carried out. RESULTS: CMA/CNV-seq had detected pathogenic variants in 2 cases which had failed karyotyping analysis. Two hundred and twenty one fetal chromosomal abnormalities were detected by karyotyping analysis, among which 187 were detected by CMA/CNV-seq. CMA/CNV-seq analysis of 23 cases with balanced chromosome structural aberrations and 10 cases with low proportion mosaicisms (including a marker chromosome) had yielded a negative result. In addition, 26 cases (26/1 841, 1.4%) with pathogenic CNVs were discovered among those with a normal karyotype, of which 13 (50.0%) were recurrent CNVs associated with neurocognitive impairment, with 22q11.21 microdeletions and microduplications being the most common types (26.92%). CONCLUSION: The combination of karyotyping analysis and CMA/CNV-seq not only increased the rate of prenatal diagnosis, but also complemented with each other, which has facilitated genetic counseling and formulation of prenatal diagnosis strategy for the affected families.

[Clinical features and genetic analysis of two fetuses with ring chromosome 21 mosaicism].

OBJECTIVE: To investigate the perinatal clinical phenotype and genetic characteristics of two fetuses with ring chromosome 21 mosaicisms. METHODS: Two fetuses who were diagnosed at the Xiamen Maternal and Child Health Care Hospital in November 2021 were selected as the study subjects. Clinical data of the two fetuses were collected. Conventional G-banded karyotyping and chromosomal microarray analysis (CMA) were carried out for the fetuses and their parents. RESULTS: Prenatal ultrasonography of fetus 1 has revealed absence of nasal bone, ventricular septal defect, persistent left superior vena cava, and mild tricuspid regurgitation. Chromosomal karyotyping was 46,X?,dic r(21;21)(p12q22;q22p12)[41]/45,X?,-21[9]. CMA has revealed a 30.00 Mb quadruplication at 21q11.2q22.3 and a 3.00 Mb deletion at 21q22.3. For fetus 2, ultrasonography has revealed pointed echo of the nasal bone. The fetus was found to have a karyotype of 46,X?,r(21)(p12q22)[83]/45,X?,-21[14]/46,X?,dic r(21;21)(p12q22;q22p12)[3]. CMA has revealed a 5.10 Mb quadruplication at 21q22.12q22.3 and a 2.30 Mb deletion at 21q22.3. CONCLUSION: The perinatal phenotype of the two fetuses with ring chromosome 21 mosaicisms is related to the duplication of chromosomal segments near the breakpoints of the chromosomal deletions. The combined chromosomal karyotyping and CMA has enabled prenatal diagnosis and genetic counseling for these families.

Fetal Tethered Spinal Cord: Diagnostic Features and Its Association with Congenital Anomalies.

OBJECTIVE: We assessed the frequency and type of associated congenital anomalies encountered with fetal tethered spinal cord (TSC) determined prenatally. METHOD: A retrospective review was conducted based on the associated fetal abnormalities following diagnosis of low-lying fetal conus medullaris during the prenatal ultrasound. RESULTS: Of the 26 fetuses with low-lying conus medullaris, four were solitary TSC and 22 had TSC combined with associated congenital malformations, including four cases with spina bifida occulta, four cases with spina bifida aperta, one case with severe hydrocephalus, and 13 cases with multisystem congenital malformations. Among all the 13 cases with combined multisystem congenital malformations, four cases had vertebral defects, anal anomalies, cardiac defects, trachea-esophageal fistula, renal anomalies, and limb anomalies (VACTERL) syndrome, two cases had combined kidney development abnormalities, one case had cloacal exstrophy (OEIS syndrome), and six cases had chromosomal abnormalities (one case of chromosome 7q deletion, two cases of trisomy 13 syndrome, one case of trisomy 18 syndrome, one case of trisomy 9 syndrome, and one case of chromosome 4p deletion). CONCLUSIONS: Low-lying conus medullaris found during prenatal ultrasound examination were often associated with neural tube malformations or multi-systemic complex developmental malformations. The frequency of chromosomal abnormalities was 23.1%.

The relationship between pregnancy stress and mental health of the pregnant women: the bidirectional chain mediation roles of mindfulness and peace of mind.

Objective: This study aimed to investigate the relationship between pregnancy stress and mental health of the pregnant women, employing a positive psychology perspective. Specifically, the study sought to explore how the two positive psychological qualities of mindfulness and peace of mind may serve as potential mediators in the association between pregnancy stress and mental health of the pregnant women. Methods: Seven hundreds and thirteen pregnant women seeking care at the First Affiliated Hospital of Sun Yat-Sen University were included in this study. The participants completed a self-report demographic questionnaire, as well as several validated scales including the Pregnancy Pressure Scale (PPS), Mindful Attention Awareness Scale (MAAS), Peace of Mind Scale (PoMS), and Chinese Health Questionnaire (CHQ). The Amos 23.0 system was utilized to construct structural equation models. Results: A total of 713 participants had an average age of 29.46 ± 4.81 years and an average gestational age of 24.26 ± 22.66 weeks. Out of the pregnant women, 163 (22.9%) experienced moderate or higher levels of pregnancy stress (PPS > 1), while 212 (29.7%) exhibited mental distress (CHQ > 3). Pregnancy stress exhibited a positive association with mental distress, while displaying negative associations with mindfulness and peace of mind. Mindfulness and peace of mind were negatively associated with mental distress. By employing structural equation modeling, the analysis revealed that mindfulness and peace of mind acted as partial mediators in the relationship between pregnancy stress and mental health. Furthermore, the identified models exhibited bidirectional sequential mediating pathways, suggesting that the pathways of mindfulness ↔ peace of mind mitigated the harmful influence of pregnancy stress on the mental health of pregnant women. Conclusion: This study adds to the current body of knowledge by investigating the relationships among mindfulness, peace of mind, pregnancy stress, and mental health in pregnant women. From a positive psychology framework, it provides valuable understanding of the intricate dynamics between pregnancy stress and protective factors of mental health. Consequently, interventions aimed at bolstering positive psychological qualities in pregnant women should prioritize the cultivation of mindfulness to foster peace of mind, or alternatively, the cultivation of peace of mind to enhance mindfulness, ultimately leading to improved mental health outcomes.

An Analysis on the Factors for Cervical Insufficiency Causing Adverse Emotions Among Pregnant Women at Different Gestation Phases.

Background: To analyze the anxiety, depression, and related factors among pregnant women with cervical insufficiency, so as to provide a reference for clinical psychological intervention as an adjuvant therapy. Methods: A total of 101 cases in China with cervical insufficiency were included in the observation group by a convenience sampling method, and 114 normal healthy women of childbearing age were selected as the control group. Participants were investigated and observed for anxiety and depression by SAS and SDS, respectively, to analyze the emotional state and influencing factors of the patients with cervical insufficiency. Stratified by the first, second and third trimesters, our study used whether depressive or not and whether anxiety or not as the dichotomous variables. A multivariate Logistic regression was adopted to analyze the influencing factors. Relevant influencing factors were screened out by the forward stepwise method in combination with professional knowledge and the number of variables. Results: There were statistical significant differences in SAS and SDS between observation group and control group and the incidence rate of anxiety and depression was higher in pregnant women with CI. Multivariate Logistic regression demonstrated that history of abnormal pregnancy was the main influencing factor for anxiety and depression in the early and middle gestation phases, and cervical insufficiency was the factor influencing the anxiety in early gestation and both anxiety and depression in the late gestation phase. Conclusion: Cervical insufficiency may have a negative impact on the emotions of pregnant women. Individualized and targeted mental care should be added into clinic work to prevent negative outcomes.

Meta-analysis: association of homocysteine with recurrent spontaneous abortion.

We analyzed the differences in serum homocysteine levels between patients with a history of recurrent spontaneous abortion (RSA) and those who had not experienced pregnancy-related complications. To this end, we retrieved literature and data on the association of RSA and serum homocysteine levels published before September 1st 2019 from the PubMed, EMBASE, China National Knowledge Infrastructure, and Wanfang databases. We further narrowed our literature review by focusing on peer-reviewed and full-text literature reporting on studies that used similar research methods and provided raw data or means and standard deviations while reporting results. Utilizing Stata 12.0 for a combined statistical analysis of the data, we assessed the quality of the included literature using the Newcastle Ottawa Scale. Patients who experienced RSA had higher serum homocysteine levels than the controls, with the difference being statistically significant (p < .05). High serum homocysteine levels may be an important risk factor for RSA, indicating that homocysteine may be useful as a noninvasive marker for the diagnosis of recurrent abortions.

Overexpression of the PLK4 Gene as a Novel Strategy for the Treatment of Autosomal Recessive Microcephaly by Improving Centrosomal Dysfunction.

Autosomal recessive microcephaly and chorioretinopathy (MCCRP) is a neurodevelopmental disorder characterized by delayed psychomotor development, growth retardation with dwarfism, and ocular abnormalities, and its occurrence has been found to be closely related to variants of the gene encoding centrosomes. However, the association between centrosomal duplication defects and the etiology of microcephaly syndromes is poorly understood. It is well known that polo-like kinase 4 (PLK4) is a key regulator of centriole duplication, and the abnormalities of centrosomal function caused by its protein variation need to be further explored in the pathogenesis of microcephaly. In our study, we found that a patient with microcephaly and chorioretinopathy harbored compound heterozygous missense variants NM_014264.4: c.2221C > T (p.Gln741*) and NM_014264.4: c.2062 T > C (p.Tyr688His) in the PLK4 gene. Overexpression experiments of the variant PLK4 proteins then showed that the G741 variant rather than the T688H variant had lost centrosomal amplification ability, and the G741 variant but not the T688H variant induced centrosomal replication disorder, which further inhibited cell proliferation, cycle division and cytoskeleton morphology in HeLa cells. Moreover, the overexpression of the two variant proteins had inconsistent effects on the target protein PLK4 by western blot analysis, also indicating that T688H variant overexpression is not functionally equivalent to WT-PLK4 overexpression. Therefore, all data support the idea that the PLK4 mutation induces centriolar duplication disorder and reduces the efficiency of mitosis inducing cell death or cell proliferation in the etiology of microcephaly disorder.

Prenatal diagnosis of familial recessive PIGN mutation associated with multiple anomalies: A case report.

OBJECTIVE: We present a novel homozygous splice site mutation in the PIGN gene identified by whole exome sequencing and explored the genotype-phenotype correlation. CASE REPORT: A healthy 32-year-old woman underwent an ultrasound at 13 + 5 weeks of gestation. The ultrasound revealed multiple anomalies again including cystic hygroma, omphalocele and a ventricular septal defect. The pregnancy was subsequently terminated, and whole exome sequencing revealed a novel homozygous splice site mutation in the PIGN gene c.963 G > A (p.Gln321Gln). The same variant was also detected by pedigree-based Sanger sequencing in both parents as heterozygous, while they had normal karyotypes. CONCLUSION: Our case report enhances the phenotype-genotype correlation associated with homozygous loss of function mutations in the PIGN gene.

The role of DNA methylation in syndromic and non-syndromic congenital heart disease.

Congenital heart disease (CHD) is a common structural birth defect worldwide, and defects typically occur in the walls and valves of the heart or enlarged blood vessels. Chromosomal abnormalities and genetic mutations only account for a small portion of the pathogenic mechanisms of CHD, and the etiology of most cases remains unknown. The role of epigenetics in various diseases, including CHD, has attracted increased attention. The contributions of DNA methylation, one of the most important epigenetic modifications, to CHD have not been illuminated. Increasing evidence suggests that aberrant DNA methylation is related to CHD. Here, we briefly introduce DNA methylation and CHD and then review the DNA methylation profiles during cardiac development and in CHD, abnormalities in maternal genome-wide DNA methylation patterns are also described. Whole genome methylation profile and important differentially methylated genes identified in recent years are summarized and clustered according to the sample type and methodologies. Finally, we discuss the novel technology for and prospects of CHD-related DNA methylation.

Clinical Utility of the Prenatal BACs-on-Beads™ Assay in Invasive Prenatal Diagnosis.

Background: The prenatal BACs-on-Beads™ (PNBoBs™) assay has been applied worldwide for prenatal diagnosis. However, there are neither guidelines nor consensus on choosing patients, sample types, or clinical pathways for using this technique. Moreover, different perspectives have emerged regarding its clinical value. This study aimed to evaluate its clinical utility in the context of clinical practice located in a prenatal diagnostic center in Xiamen, a city in southeast China. Methods: We tested 2,368 prenatal samples with multiple referral indications using both conventional karyotyping and PNBoBs™. Positive results from PNBoBs™ were verified using current gold-standard approaches. Results: The overall rates for the detection of pathogenic copy number variation (pCNV) by karyotyping and PNBoBs™ were 1.9% (46/2,368) and 2.0% (48/2,368), respectively. The overall detection rate of karyotyping combined with PNBoBs™ for pCNV was 2.3% (54/2,368). A total of 13 cases of copy number variation (CNV)with a normal karyotype were detected by PNBoBs™. Another case with a normal karyotype that was detected as a CNV of sex chromosomes by PNBoBs™ was validated to be maternal cell contamination by short tandem repeat analysis. Conclusion: Karyotyping combined with PNBoBs™ can improve both the yield and efficiency of prenatal diagnosis and is appropriate in the second trimester in all patients without fetal ultrasound anomalies who undergo invasive prenatal diagnosis.

Mutation Analysis of COL1A1 and COL1A2 in Fetuses with Osteogenesis Imperfecta Type II/III.

AIM: To analyze COL1A1/2 mutations in prenatal-onset OI for determine the proportion of mutations in type I collagen genes among prenatal onset OI and to provide additional data for genotype-phenotype analyses. MATERIAL AND METHODS: Ten cases of severe fetal short-limb dwarfism detected by antenatal ultrasonography were referred to our center. Before the termination of pregnancy, cordocentesis was performed for fetal karyotype and COL1A1/2 gene sequencing analysis. Postmortem radiographic examination was performed at all instances for definitive diagnosis. RESULTS: COL1A1 and COL1A2 SNP and mutations were identified in all the cases. Among these, one synonymous SNP and four synonymous SNPs were recognized in COL1A1/2, respectively, seven cases have distinct heterozygous mutations and six new COL1A1/2 gene mutations were identified. CONCLUSION: There has been substantial progress in the identification of the molecular defects responsible for skeletal dysplasias. With the constant increase in the number of identified mutations in COL1A1 and COL1A2, genotype-phenotype correlation is becoming increasingly pertinent.

[Diagnosis of a fetus with X-linked hydrocephalus due to mutation of L1CAM gene].

OBJECTIVE: To explore the genetic basis for a case of recurrent fetal congenital hydrocephalus. METHODS: Next-generation sequencing was carried out for the fetus, the gravida and two of her sisters. RESULTS: The fetus was found to harbor a c.1765T>C (p.Tyr589His) mutation in exon 14 of the L1CAM gene, which was derived from the gravida. CONCLUSION: Male fetuses with recurrent hydrocephalus should be subjected to testing of the L1CAM gene to facilitate genetic counseling and prenatal diagnosis.

Diagnosis of Prenatal-Onset Achondrogenesis Type II by a Multidisciplinary Assessment: A Retrospective Study of 2 Cases.

AIM: Achondrogenesis type II is a rare, lethal osteochondrodysplasia with considerable phenotypic heterogeneity. We describe our experience in diagnosing prenatal-onset achondrogenesis type II by a multidisciplinary assessment. METHODS: Two cases of fetal achondrogenesis type II were analyzed retrospectively using prenatal ultrasound evaluation, postnatal radiographic diagnosis, and molecular genetic testing of COL2A1. RESULTS: A causative mutation in the COL2A1 gene was found in both patients. Combined with postnatal radiographic examination, the final diagnosis of achondrogenesis type II was made. CONCLUSION: Our findings emphasize the importance of a multidisciplinary assessment for the definitive diagnosis of achondrogenesis type II, which is paramount for proper genetic counseling.

Diagnosis of fetal osteogenesis imperfecta by multidisciplinary assessment: a retrospective study of 10 cases.

OBJECTIVE: To describe our 2 year experience in diagnosing prenatal-onset osteogenesis imperfecta (OI) by multidisciplinary assessment. METHODS: We retrospectively analyzed 10 cases of fetal OI by using prenatal ultrasound evaluation, postnatal radiographic diagnosis, and molecular genetic testing of COL1A1/2. RESULTS: By postnatal radiographic examination, five patients were diagnosed with type II OI and five were diagnosed with type III OI. A causative variant in the COL1A1 gene was found in four cases of type II and one case of type III OI; a causative variant in the COL1A2 gene was found in two cases of type III OI. CONCLUSION: The definitive diagnosis of fetal OI should be accomplished using a multidisciplinary assessment, which is paramount for proper genetic counseling. With the discovery of COL1A1/2 gene variants as a cause of OI, sequence analysis of these genes will add to the diagnostic process.

[Clinical application of real-time PCR for the detection of genetic mutations underlying spinal muscular atrophy].

OBJECTIVE: To verify the reliability of real-time PCR for the detection of genetic mutations underlying spinal muscular atrophy (SMA) and establish quality control for clinical testing. METHODS: Thirty-five patients, 61 first-degree relatives, 61 healthy controls and 7 prenatal cases which were previously genotyped by multiplex ligation-dependent probe amplification (MLPA) were tested with Roche LightCycler 480 and Bio-Rad CFX96 (TM) real-time PCR machines for relative quantification of copy number of SMN1 exon 7. RESULTS: Genotyping detected by relative quantitative real-time PCR were consistent with the results of MLPA. Both types of real-time PCR machines could accurately distinguish different SMN1 copy numbers despite certain systematic differences between the two platforms. CONCLUSION: The reliability of real-time PCR assay for detecting SMA depends on quality control. Standard database generated with known SMN1 copy number variations should be established for different instruments.

Rapid prenatal diagnosis of common numerical chromosomal abnormalities by high-resolution melting analysis of segmental duplications.

BACKGROUND: Rapid aneuploidy detection (RAD) methods constitute important complements to karyotyping in prenatal diagnosis. We evaluated the effectiveness of a method called high-resolution melting analysis of segmental duplications (SD-HRM) to serve as an alternative RAD method in prenatal diagnosis of common numerical chromosomal abnormalities (NCAs). METHODS: We designed eight primary SD-HRM assays for the detection of chromosomes 13, 18, 21, X, and Y; 50 chorionic villus, 1105 amniotic fluid, and 395 cord blood samples were examined using these eight assays. For diagnosing samples that could not be diagnosed using primary assays, additional assays were designed for each target chromosome. RESULTS: The success rate of eight primary SD-HRM assays ranged from 99.7% to 100%. For the distinguishable analyses, these eight assays attained high diagnostic sensitivities (100%) and specificities (99.9-100%). We differentiated 53 cases of NCAs from 1550 clinical samples; subsequent reference tests revealed that these assays attained 100% clinical sensitivity and specificity. The mosaic ratio of a 45,X/46,XX sample was also precisely calculated. CONCLUSIONS: The SD-HRM method was able to effectively detect common NCAs in 1550 prenatal samples. We propose that SD-HRM could serve as an effective alternative option to the currently used prenatal RAD methods.

Noninvasive prenatal testing of trisomies 21 and 18 by massively parallel sequencing of maternal plasma DNA in twin pregnancies.

OBJECTIVE: The objective of this study is to assess the performance of noninvasive prenatal testing for trisomies 21 and 18 on the basis of massively parallel sequencing of cell-free DNA from maternal plasma in twin pregnancies. METHOD: A double-blind study was performed over 12 months. A total of 189 pregnant women carrying twins were recruited from seven hospitals. Maternal plasma DNA sequencing was performed to detect trisomies 21 and 18. The fetal karyotype was used as gold standard to estimate the sensitivity and specificity of sequencing-based noninvasive prenatal test. RESULTS: There were nine cases of trisomy 21 and two cases of trisomy 18 confirmed by karyotyping. Plasma DNA sequencing correctly identified nine cases of trisomy 21 and one case of trisomy 18. The discordant case of trisomy 18 was an unusual case of monozygotic twin with discordant fetal karyotype (one normal and the other trisomy 18). The sensitivity and specificity of maternal plasma DNA sequencing for fetal trisomy 21 were both 100% and for fetal trisomy 18 were 50% and 100%, respectively. CONCLUSION: Our study further supported that sequencing-based noninvasive prenatal testing of trisomy 21 in twin pregnancies could be achieved with a high accuracy, which could effectively avoid almost 95% of invasive prenatal diagnosis procedures.

Investigation of the frequencies of prenatally diagnosed fetal chromosomal abnormalities at a single institution.

The objective of this study was to investigate, retrospectively, the frequencies of fetal chromosomal abnormalities identified in 4176 prenatal cytogenetic examinations at the Xiamen Maternity and Child Health Care Hospital over the 5-year period from October 2005 to September 2010. The frequency of abnormal fetal karyotypes was 4.6%. Numerical chromosome abnormalities were identified in 150 cases. The frequency of trisomy 21 was by far the highest, followed by trisomy 18. Structural aberrations of chromosomes were identified in 43 cases, including 21 cases with balanced and 22 cases with unbalanced chromosomal aberrations. In addition, 16 cases of apparently de novo chromosomal aberrations and 27 cases of familial inheritances were observed. Increased awareness of the frequencies of fetal chromosome abnormalities is important for the improvement of prenatal care and providing the options of termination or continuation of the pregnancy. Data obtained in this study provide the basis of a database for genetic counseling.

[Genetic counseling and clinical outcome of fetus with de novo chromosomal aberrations].

OBJECTIVE: To analyze the chromosome rearrangements and clinical outcome in fetus detected at prenatal diagnosis, and provide information for genetic counseling about de novo chromosomal aberrations. METHODS: From January 2006 to December 2009, we found 12 cases of de novo chromosomal aberrations in 2 583 cases of prenatal cytogenetic analyses and reviewed the karyotypes, other experimental analyses data, fetal ultrasound findings and clinical outcomes. RESULTS: Out of the 12 de novo chromosomal aberrations, 10 had unbalanced translocations and 2 had balanced reciprocal translocations. Eight of the 10 unbalanced translocation cases were terminated therapeutically, and 2 were delivered with full term. Neonates were phenotypically normal in the 2 cases with unbalanced translocations, but 1 had language retardation when followed up. The two balanced translocation cases were delivered with full term, and the neonates were phenotypically normal and clinical examinations were normal too. CONCLUSION: Detailed cytogenetic and molecular study will be adjunctive tools for predicting the phenotype of fetus with de novo chromosomal aberrations. Fetal ultrasound examination will provide convincible demonstration to determine the outcome of pregnancy.

Macrophage migration inhibitory factor enhances neoplastic cell invasion by inducing the expression of matrix metalloproteinase 9 and interleukin-8 in nasopharyngeal carcinoma cell lines.

BACKGROUND: Nasopharyngeal carcinoma (NPC) shows highly invasive and metastatic features. This study aims to investigate macrophage migration inhibitory factor (MIF)-induced invasion of NPC cells in vitro and the effects on matrix metalloproteinases (MMPs) and interleukin-8 (IL-8), and to study the mechanism of tumor cell invasion and metastasis in the early stage of NPC. METHODS: Two nasopharyngeal carcinoma cell lines, CNE-1 and CNE-2, were adopted in this study. The NPC cell invasion and migration were evaluated by microinvasion assay. The variation of expression percentages of MMP2- or MMP9-positive cells was detected by flow cytometry in two cell lines with or without MIF treatment. Western blotting and RT-PCR were used to assay the protein and mRNA expressions of MMP2 and MMP9. The IL-8 concentration secreted by NPC cells was compared with the cells with different treatments using ELISA. RESULTS: After treating with MIF for 48 hours, the cell numbers of CNE-1 and CNE-2 which went through the 8-microm filter membrane were increased. Compared with non-MIF treated NPC cells, significant difference could be found both in CNE-1 (P = 0.005) and CNE-2 cells (P = 0.001). The percentages of MMP9-positive cells were significantly increased in both CNE-1 [from (28.5 +/- 2.5)% to (82.4 +/- 3.5)%, P = 0.001] and CNE-2 [from (32.8 +/- 3.5)% to (86.1 +/- 1.6)%, P = 0.002]. The relative intensity of MMP9 protein expression was also enhanced in both cell lines (CNE-1: from 83.1 +/- 6.0 to 242.9 +/- 22.9, P = 0.002; CNE-2: from 84.4 +/- 4.3 to 278.9 +/- 29.7, P = 0.003). Correspondingly, the increased MMP9 mRNA expression level was significantly detectable in both cell lines. The concentration of IL-8 in the supernatant of CNE-2 was higher [(1201.8 +/- 593.3) pg/ml] after treatment. It was also remarkably higher than that in the supernatant of CNE-2 without treatment (P = 0.026). However, there was no significant difference in the concentration variation of IL-8 in CNE-1 (P = 0.581), while the IL-8 mRNA level was only enhanced in CNE-2. CONCLUSIONS: MIF can induce potent invasion of NPC cell lines in vitro, and the infiltrating lymphocytes in NPC might be responsible for the invasion and metastasis of tumor cells. MIF cytokine which is secreted by these infiltrating lymphocytes might contribute to the invasion as well as metastasis of NPC in the early stages by induction of MMP9 and IL-8 in an indirect pathway.