Paired Box Gene 2 Research Articles

Increased Local Testosterone Levels Alter Human Fallopian Tube mRNA Profile and Signaling

Fallopian tube epithelium (FTE) plays a critical role in reproduction and can be the site where High Grade Serous Ovarian Carcinoma (HGSOC) originates. Tumorigenic oviductal cells, which are the murine equivalent of human fallopian tube secretory epithelial cells (FTSEC), enhance testosterone secretion by the ovary when co-cultured with the ovary, suggesting that testosterone is part of the signaling axis between the ovary and FTSEC. Furthermore, testosterone promotes proliferation of oviductal cells. Oral contraceptives, tubal ligation, and salpingectomy, which are all protective against developing ovarian cancer, also decrease circulating levels of androgen. In the current study, we investigated the effect of increased testosterone on FTE and found that testosterone upregulates wingless-type MMTV integration family, member 4 (WNT4) and induces migration and invasion of immortalized human fallopian tube cells. We profiled primary human fallopian tissues grown in the microfluidic system SOLO-microfluidic platform -(MFP) by RNA sequencing and found that p53 and its downstream target genes, such as paired box gene 2 (PAX2), cyclin-dependent kinase inhibitor 1A (CDK1A or p21), and cluster of differentiation 82 (CD82 or KAI1) were downregulated in response to testosterone treatment. A microfluidic platform, the PREDICT-Multi Organ System (PREDICT-MOS) was engineered to support insert technology that allowed for the study of cancer cell migration and invasion through Matrigel. Using this system, we found that testosterone enhanced FTE migration and invasion, which was reversed by the androgen receptor (AR) antagonist, bicalutamide. Testosterone also enhanced FTSEC adhesion to the ovarian stroma using murine ovaries. Overall, these results indicate that primary human fallopian tube tissue and immortalized FTSEC respond to testosterone to shift expression of genes that regulate invasion, while leveraging a new strategy to study migration in the presence of dynamic fluid flow.

Differentiation of Mesenchymal Stem Cells Derived from Amniotic Membrane to Neuronal Cells and the Expression of PAX2 and NURR1 Genes

: Mesenchymal stem cells (MSCs) have different sources, including bone marrow, adipose tissue, umbilical cord, amniotic fluid, and amniotic membrane. They have immunomodulatory properties. These cells can be used for the treatment of many neurological diseases such as Parkinson’s and Alzheimer’s disease. In this study, MSCs were isolated from the amniotic membrane, and their surface markers were investigated using flow cytometry. MSCs were differentiated to osteoblasts, adipocytes, and finally, to the nerve cells under the influence of epidermal, basic fibroblast natural growth factors, and two other media. The first medium included indomethacin, butyric acid, and ascorbic acid. The second one included retinoic acid and ascorbic acid. The expression of paired box gene 2 (PAX2) and nuclear receptor related-1 (NURR1) genes were investigated using real-time polymerase chain reaction and showed higher levels than that of controls. The presence of the expression of β-tubulin III and microtubule-associated protein 2 (MAPII) was studied by immunocytochemistry. The result suggested that the second medium included retinoic acid was better than the first medium. Protecting neurons are important in neurological diseases, and the expression of mRNAs such as PAX2, NURR1, β-tubulin III, and MAPII plays an effective role in neural differentiation.

Early Evidence on Genetic Polymorphisms in Conferring A "Two-Hit" Propensity to Renal Injury in Asian Indian Children.

Congenital anomalies of the kidney and urinary tract (CAKUT) are a common cause of end-stage renal disease in children. While certain nephrogenic genes have been incriminated in these malformations, data to identify the frequency of gene polymorphisms in Asian Indian children with CAKUT are scarce. This study was done to identify the effect of polymorphisms in paired-box gene 2 (PAX2), bone morphogenetic protein (BMP)-4, angiotensin-converting enzyme (ACE), and angiotensin II receptor Type 2 (AGTR2) nephrogenic genes on the development of CAKUT. In this prospective cohort study, 158 children <12 years old (86 cases with CAKUT and 72 age-matched controls) were analyzed. DNA from both sets was extracted from peripheral blood using the Keygen DNA extraction kit, and single-nucleotide gene polymorphisms (SNPs) in PAX2, BMP-4, ACE, and AGTR2 nephrogenic genes were detected by polymerase chain reaction (PCR) using previously published primers and PCR conditions. The presence of A allele SNP for AGTR2 gene at rs3736556 was found to be significantly correlated with the development of ureteropelvic junction obstruction and vesicoureteral reflux (VUR) with the TT allelic genotype having a lower incidence of pelviureteric junction obstruction (odds ratio [OR] 0.18 [95% confidence interval [CI], 0.06-0.55], P = 0.01) and VUR (OR 0.31 [95% CI, 0.11-0.91], P = 0.03). Furthermore, on substratification of the patients with the presence of the A allele of AGTR2, 24 out of 27 patients with scarring were found to harbor the D allele of the ACE gene, thus predisposing them to further renal damage. This study points to early evidence in the implication of nephrogenic genes in development as well as predisposition to renal injury in Asian Indian patients with CAKUT.

Identification of of a PAX2 mutation from maternal mosaicism causes recurrent renal disorder in siblings

BackgroundPAX2-related disorder is an autosomal dominant disorder characterized by renal and eye abnormalities. Some patients may present with isolated renal abnormalities without obvious ocular abnormalities. It is associated with mutations in paired box gene 2 (PAX2), which is one of the families of paired box transcription factor genes. Studies on mosaicism have been limited in PAX2-related disorder, as only three families with mosaic PAX2 mutations have been reported in the literature. MethodsThe proband with multicystic dysplastic kidneys from a Chinese family was recruited in our study. Detailed clinical symptoms were enquired. Trio-based whole exome sequencing (WES), SNP array, sanger sequencing and droplet digital PCR (ddPCR) were used to characterize etiology in the proband. Prenatal diagnosis was performed through amniocentesis and prenatal ultrasound when the proband's mother was further pregnant at 20 weeks. ResultsA heterozygous missense mutation in PAX2 (c.194 T > C) was identified in the proband. His asymptomatic mother has the same mutation with somatic mosaicism ratio of 22%. The mutation was also detected in the fetus. Prenatal ultrasound showed that bilateral hyperechogenic kidneys with decrease of renal size. ConclusionsThis is the first report on PAX2 mosaicism in a Chinese family. Identifying PAX2 mosaicism provides more evidence for estimating recurrence risk. Our findings have important implications on genetic counseling for patients with PAX2-related disorder and provide an effective diagnostic technology for mosaicism.

Spectrum of Mutations in Pediatric Non-glomerular Chronic Kidney Disease Stages 2-5.

Renal hypodysplasia and cystic kidney diseases, the common non-glomerular causes of pediatric chronic kidney disease (CKD), are usually diagnosed by their clinical and imaging characteristics. The high degree of phenotypic heterogeneity, in both conditions, makes the correct final diagnosis dependent on genetic testing. It is not clear, however, whether the frequencies of damaged alleles vary among different ethnicities in children with non-glomerular CKD, and this will influence the strategy used for genetic testing. In this study, 69 unrelated children (40 boys, 29 girls) of predominantly Han Chinese ethnicity with stage 2–5 non-glomerular CKD caused by suspected renal hypodysplasia or cystic kidney diseases were enrolled and assessed by molecular analysis using proband-only targeted exome sequencing and array-comparative genomic hybridization. Targeted exome sequencing discovered genetic etiologies in 33 patients (47.8%) covering 10 distinct genetic disorders. The clinical diagnoses in 13/48 patients (27.1%) with suspected renal hypodysplasia were confirmed, and two patients were reclassified carrying mutations in nephronophthisis (NPHP) genes. The clinical diagnoses in 16/20 patients (80%) with suspected cystic kidney diseases were confirmed, and one patient was reclassified as carrying a deletion in the hepatocyte nuclear factor-1-beta gene (HNF1B). The diagnosis of one patient with unknown non-glomerular disease was elucidated. No copy number variations were identified in the 20 patients with negative targeted exome sequencing results. NPHP genes were the most common disease-causing genes in the patients with disease onsets above 6 years of age (14/45, 31.1%). The children with stage 2 and 3 CKD at onset were found to carry causative mutations in paired box gene 2 (PAX2) and HNF1B gene (11/24, 45.8%), whereas those with stage 4 and 5 CKD mostly carried causative mutations in NPHP genes (19/45, 42.2%). The causative genes were not suspected by the kidney imaging patterns at disease onset. Thus, our data show that in Chinese children with non-glomerular renal dysfunction caused by renal hypodysplasia and cystic kidney diseases, the common causative genes vary with age and CKD stage at disease onset. These findings have the potential to improve management and genetic counseling of these diseases in clinical practice.

Whole genome sequence analysis identifies a PAX2 mutation to establish a correct diagnosis for a syndromic form of hyperuricemia.

Hereditary hyperuricemia may occur as part of a syndromic disorder or as an isolated nonsyndromic disease, and over 20 causative genes have been identified. Here, we report the use of whole genome sequencing (WGS) to establish a diagnosis in a family in which individuals were affected with gout, hyperuricemia associated with reduced fractional excretion of uric acid, chronic kidney disease (CKD), and secondary hyperparathyroidism, that are consistent with familial juvenile hyperuricemic nephropathy (FJHN). However, single gene testing had not detected mutations in the uromodulin (UMOD) or renin (REN) genes, which cause approximately 30-90% of FJHN. WGS was therefore undertaken, and this identified a heterozygous c.226G>C (p.Gly76Arg) missense variant in the paired box gene 2 (PAX2) gene, which co-segregated with renal tubulopathy in the family. PAX2 mutations are associated with renal coloboma syndrome (RCS), which is characterized by abnormalities in renal structure and function, and anomalies of the optic nerve. Ophthalmological examination in two adult brothers affected with hyperuricemia, gout, and CKD revealed the presence of optic disc pits, consistent with optic nerve coloboma, thereby revising the diagnosis from FJHN to RCS. Thus, our results demonstrate the utility of WGS analysis in establishing the correct diagnosis in disorders with multiple etiologies.

Clinical and genetic variability of PAX2-related disorder in the Japanese population.

Pathogenic variants of paired box gene 2 (PAX2) cause autosomal-dominant PAX2-related disorder, which includes renal coloboma syndrome (RCS). Patients with PAX2-related disorder present with renal and ophthalmological pathologies, as well as with other abnormalities, including developmental problems and hearing loss. We sequenced PAX2 in 457 patients with congenital anomalies of the kidney and urinary tract or with renal dysfunction of unknown cause and identified 19 different pathogenic variants in 38 patients from 30 families (6.5%). Thirty-four patients had renal hypodysplasia or chronic kidney disease of unknown cause, and three had focal segmental glomerulosclerosis. Although no obvious genotype-phenotype correlation was observed, six of the seven patients who developed end-stage renal disease in childhood had truncating variants. Twenty-three patients had ocular disabilities, mostly optic disc coloboma. Non-renal and non-ophthalmological manifestations included developmental disorder, electrolyte abnormality, and gonadal abnormalities. Two unrelated patients had congenital cystic adenomatoid malformations in their lungs. Six of ten probands with PAX2 mutation identified by next-generation sequencing did not show typical RCS manifestations. We conclude that PAX2-related disorder has a variable clinical presentation and can be diagnosed by next-generation sequencing even in the absence of typical RCS manifestations.

PAX2 expression is correlated with better survival in tamoxifen-treated breast carcinoma patients.

PAX2 (paired box gene 2) is a transcription factor, which is involved in both cell proliferation and carcinogenesis. This study aimed to investigate PAX2 expression in tamoxifen resistant (TAM-R) and tamoxifen sensitive (TAM-S) breast carcinoma patients and analyze its correlation with clinicopathological characteristics and survival. Immunohistochemical analysis was performed to evaluate PAX2 protein expression in 36 TAM-R and 36 TAM-S formalin-fixed paraffin-embedded (FFPE) breast tumor tissues. Data analysis indicated that PAX2 expression was significantly higher in TAM-S group in comparison to TAM-R (P = 0.014). Overexpression of PAX2 was significantly correlated with perineural invasion (PNI) (P = 0.025). Kaplan-Meier survival analysis showed significant association between high expression of PAX2 and better disease-free survival (P < 0.001) and also overall survival (P = 0.031). Multivariate cox regression analysis demonstrated that patients with increased expression of PAX2 have a trend toward improved disease free survival (OR = 0.065, 95% CI: 0.009-0.476; P = 0.007) and overall survival (OR = 0.147, 95% CI: 0.020-1.105; P = 0.062). Our data suggested that high expression of PAX2 could be associated with better survival in estrogen receptor positive tamoxifen-treated breast carcinoma patients.

PAX2 regulates NRP-1 expression in renal tubular epithelial cellsto promote epithelial-to-mesenchymal transition and renal fibrosis

To observe the expression of neuropilin-1 (NRP-1) induced by paired-box gene 2 (PAX2) during the process of epithelial-to-mesenchymal transition (EMT) and renal fibrosis in unilateral ureteral obstruction (UUO) model in rats, and explore the mechanism of EMT induced by PAX2. Methods: The recombinant lentivirus expression vector for PAX2 was constructed and transfected into rat normal renal tubular epithelial cell line (NRK52E). The experimental cells were divided into three groups: transfection group, empty vector group, and normal group. E-cadherin and α-SMA were detected by western blot and real-time PCR. Expression of NRP-1 was detected by western blot, real-time PCR, and immunofluorescence. Sixty male Wistar rats were randomly divided into two groups: the sham-operation group (n=30) underwent left ureteral dissection, the UUO group (n=30) underwent left ureteral ligation. Post-operation on days 3, 7, 14, 21 and 28, 6 rats from each of the groups were sacrificed and the obstructed kidneys were dissected out. The histopathological changes were observed by hematoxylin-eosin and Masson staining. E-cadherin and α-SMA were detected by western blot and immunohistochemistry. Expression of NRP-1 and PAX2 were determined by western blot, immunohistochemistry, and real-time PCR. Results: Expression of NRP-1 mRNA and protein and α-SMA protein increased (P&lt;0.05) while E-cadherin protein expression decreased (P&lt;0.05) in the transfection group as compared to the empty vector group in vitro. In the UUO group, fibrosis was obvious, and there was decreased expression of E-cadherin protein (P&lt;0.05) and increased expression of α-SMA protein and NRP-1 mRNA and protein (P&lt;0.05) in comparison to the sham group. Conclusion: NRP-1 maybe mediate PAX2-induced EMT in renal tubular epithelial cells and renal fibrosis.

PAX2 (Paired box gene 2)

Review on PAX2 (paired box gene 2), with data on DNA, on the protein encoded, and where the gene is implicated.

Genetic association between PAX2 and mullerian duct anomalies in Han Chinese females.

The study aims to investigate the genetic association between paired box gene 2 (PAX2) and mullerian duct anomalies (MDA) in Chinese Han females. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) was used to identify the genotypes of three tag single nucleotide polymorphisms (SNPs) in PAX2 in 362 MDA cases and 406 controls. We found that one tag SNP (rs12266644) of PAX2 was associated with susceptibility to MDA. The genotype distributions of the SNP rs12266644 have a statistically significant difference in the MDA patients and controls with a p value = 0.008. In the dominant model, we also observed that the GT + TT genotype increased the risk for MDA (p = 0.015, OR = 1.637, 95% CI = 1.096-2.443). The polymorphism rs12266644 of PAX2 might be a risk factor for MDA in Chinese Han females.

Bilateral Renal Dysplasia, Nephroblastomatosis, and Bronchial Stenosis. A New Syndrome?

Bilateral nephroblastomatosis (NB) is an uncommon renal anomaly characterized by multiple confluent nephrogenic rests scattered through both kidneys, with only a limited number of cases reported in the medical literature. Some of these children may have associated either Perlman or Beckwith–Wiedemann syndrome and others do not demonstrate syndromic features.We report a full-term boy with anteverted nose, bilateral bronchial stenosis due to lack of cartilage, bilateral obstructive renal dysplasia and NB with glomeruloid features. The infant had visceromegaly, but neither gigantism nor hemihypertrophy.Immunohistochemistry for PAX2 (Paired box gene-2) and WT-1 (Wilms Tumor 1) were strongly positive in the areas of NB. GLEPP-1 (Glomerular Epithelial Protein) did not stain the areas of NB with a glomeruloid appearance, but was positive in the renal glomeruli as expected. We found neither associated bronchial stenosis nor the histology of NB resembling giant glomeruli in any of the reported cases of NB.

Upregulation of PAX2 Promotes the Metastasis of Esophageal Cancer through Interleukin-5

Background/Aims: This study investigated the clinical relevance and biological function of paired box gene 2 (PAX2) in esophageal squamous cell carcinoma (ESCC). Methods/Results: Results showed that PAX2 expression was significantly increased in tumor tissues and that its expression correlated with the ESCC stage (P = 0.001), lymph node metastasis (pN, P = 0.019) and lymphatic invasion (P = 0.005) in 120 ESCC tissue specimens by immunohistochemistry. Furthermore, PAX2 overexpression resulted in markedly reduced cell proliferation but increased metastasis capacity in ESCC TE-1 and Eca-109 cells. Knockdown of PAX2 expression with a short hairpin RNA confirmed a role in the promotion of metastasis in ESCC cells. mRNA microarray screening revealed that PAX2 overexpression affected multiple genes that function in multiple pathways. Interleukin-5 (IL-5), which was induced by PAX2 and has been shown to promote tumor metastasis, was further studied in greater detail. Two PAX2 binding sites were identified in the IL-5 promoter, and PAX2 was observed to stimulate IL-5 promoter activity and IL-5 expression in esophageal cancer cells. Chromatin immunoprecipitation (ChIP) confirmed the direct binding of PAX2 in the IL-5 promoter. The expression of PAX2 mRNA significantly correlated with that of IL-5 in normal esophageal and ESCC tissues. Conclusion: These findings demonstrate that PAX2 is overexpressed in esophageal carcinoma and IL-5 is identified as PAX2's effector for metastasis.

Identification of two promoters for human D-amino acid oxidase gene: implication for the differential promoter regulation mediated by PAX5/PAX2.

D-amino acid oxidase (DAO) is a flavoenzyme that metabolizes d-amino acids. Until now, the DAO expression mechanism is still unclear. Our assessment of human DAO (hDAO) promoter activity using luciferase reporter system indicated the proximal upstream region of exon1 (-237/+1) has promoter activity (P1). Interestingly, we identified an alternative promoter in the proximal upstream region of exon2 (+4,126/+4,929) (P2). This alternative promoter has stronger activity than that of P1. Our results also revealed a negative regulatory segment (+1,163/+1,940) in intron1; that would act in concert with P1 and P2. Bioinformatics analyses elucidated the conservation of transcription factor PAX5 family binding sites among species. These sites (-60/-31) and (+4,464/+4,493), locate in P1 and P2 of hDAO, respectively. Gel shift assays demonstrated P1 contains a site (-60/-31) for PAX5 binding while P2 has three sites for both paired box gene 2 (PAX2) and paired box gene 5 (PAX5) binding. The dual roles of PAX5 family in regulating hDAO transcription by modulating promoter activity of P1 and activating promoter activity of P2 were implicated based on the site-directed mutagenesis experiment. Altogether, our data suggested the differential regulation of hDAO expression by two promoters whose activities may be modulated by the binding of PAX2 and PAX5.

The potential signal pathway between PAX2 and CD2AP in the renal interstitial fibrosis disease

Paired box gene 2 (PAX2) can regulate tissue development and cellular differentiation, and it is associated with renal diseases. CD2-associated protein (CD2AP) is an adaptor protein involving in a variety of physiological and disease processes. Renal interstitial fibrosis (RIF) is a hallmark of common progressive chronic diseases which lead to renal failure. This study was performed to investigate whether there was a potential signal pathway between PAX2 and CD2AP in RIF rats induced by unilateral ureteral obstruction (UUO). Eighty Wistar male rats were divided into two groups randomly: sham operation group (SHO) and model group subjected to UUO (GU), n = 40. The model was established by left ureteral ligation. Renal tissues were collected at 14 d and 28 d after surgery. RIF index, cell apoptosis index, protein expression of PAX2, CD2AP, transforming growth factor-βl (TGF-β1), collagen-IV (Col-IV), fibronectin (FN) in renal interstitium and renal tissue, and mRNA expression of PAX2, CD2AP, and TGF-β1 in renal tissue were detected. Compared with that in the SHO group, the PAX2 and CD2AP expressions (mRNA and protein) were significantly increased (p < 0.01). Protein expressions of TGF-β1, Col-IV, and FN, and RIF index or cell apoptosis index in the GU group were markedly elevated than those in the SHO group (all p < 0.01). PAX2 or CD2AP was positively correlated with TGF-β1, Col-IV, and FN, and RIF index or cell apoptosis index (all p < 0.05). Furthermore, PAX2 was positively correlated with CD2AP (p < 0.05). In conclusion, the expression of PAX2 or CD2AP was increased in RIF rats, and PAX2 was positively correlated with CD2AP. There might be a potential signaling pathway between PAX2 and CD2AP in RIF disease. Further research is needed to determine the association in RIF disease.

Function of L-carnitine on rat renal interstitial fibrosis with unilateral ureteral obstruction

Objective This study was performed to investigate the influence on rat renal interstitial fibrosis with unilateral ureteral obstruction by L-caruitine (LC),and examine significance and changes of paired box gene-2 (PAX2),α-smooth muscle actin (α-SMA) and transforming growth factor-β1 (TGF-β1) in this process.Methods Thirty-six rats were divided into three groups randomly:Sham operation group (Sham),model group subjected to unilateral ureteral obstruction (UUO),and L-carnitine-treated group (LC).Kidney tissues of every group were taken by operation in 7th and 14th day,and protein expression levels of α-SMA,PAX2 and TGF-β1 were detected by different ways.Results PAX2 mRNA was significantly reduced in rat kidney tissue in LC group compared to UUO group (P ＜ 0.05),but increased compared to Sham group (P ＜ 0.05).Inmunocheinistry shows significant discrepancy in PAX2 between each groups (P ＜ 0.05).Average absorbance was (0.5547 ± 0.0593),(0.4225 ± 0.0298) and (0.2556 ± 0.0359) in UUO,LC and Sham group respectively at 7 days as well as (0.6376 ±0.0448),(0.4731 ±0.0342) and (0.2480 ±0.0256) correspondingly at 14 days.Protein expression of α-SMA and TGF-β1 in rat kidney tissue indicates was significantly reduced in LC group compared to UUO group (P ＜ 0.05),but increased compared to Sham group (P ＜ 0.05) at days 7 and 14.Conclusion L-carnitine could effectively decrease renal injury,down-regulate the level of re-expression of PAX2,inhibit expression of α-SMA,TGF-β1.Therefore it could reduce renal interstitial fibrosis and cell apoptosis by some mechanism. Key words: L-carnitine; Unilateral ureteral obstruction; Paired box gene-2; α-smooth muscle actin; Transforming growth factor-β1

PAX2 in 192 Chinese women with Müllerian duct abnormalities: mutation analysis

The paired box gene 2 (PAX2) has been proven to be a crucial gene during organogenesis of the urogenital system in mice models. This study was aimed to explore the relationship between PAX2 mutations and human Müllerian duct abnormalities (MDA). A total of 192 Chinese MDA patients (15 cases of uterine aplasia and 177 of incomplete Müllerian fusion) and 192 ethnic-matched controls were recruited from 2009 to 2011. Coding regions of PAX2 of MDA cases were amplified and sequenced. One rare novel synonymous variant (c.320G>A) was discovered in one patient with uterus didelphys, whereas this variant was not found in the control group. Mutations in PAX2 may be not a common cause of MDA.The upper part of the vagina, the uterus and the Fallopian tubes is derived from the embryonic Müllerian duct. Müllerian duct malformation consists of a miscellaneous group of congenital anomalies of the female reproductive duct. To date, researchers have done a large amount of work to define the aetiology of this malformation; however, it remains a mystery. Paired box gene 2 (PAX2) has been proven to be a crucial gene during organogenesis of the urogenital system in mice models. This study was aimed to explore the relationship between PAX2 mutations and human Müllerian duct abnormalities (MDA). A total of 192 Chinese MDA patients (15 cases of uterine aplasia and 177 of incomplete Müllerian fusion) and 192 ethnic-matched controls were recruited from 2009 to 2011. Coding regions of PAX2 were amplified and sequenced. One rare novel synonymous variant (c.320G>A) was discovered in one patient with uterus didelphys, whereas this variant was not found in the control group. In the Han Chinese population, mutations in PAX2 may be not a common cause of MDAs.

Alport-like glomerular basement membrane changes with renal-coloboma syndrome

Autosomal dominant mutations in paired box gene 2 (PAX2), on chromosome 10q24, are responsible for renal coloboma syndrome (RCS). The role of PAX2 in glomerular basement membrane (GBM) formation and maintenance remains unknown. We report a case of a 13-year-old Japanese girl who had both optic disk coloboma and renal insufficiency. Her father and sister also had both coloboma and renal dysfunction. Renal pathological findings revealed a basket-weave pattern of the GBM, which was compatible with Alport syndrome, but type IV collagen α5 staining was normal. The patient's findings of coloboma and renal dysfunction suggested that she had RCS, and genetic analysis revealed a PAX2 heterozygous mutation in exon 2 (c.76dup, p.Val26Glyfsx27) without any mutations of COL4A3, COL4A4, and COL4A5, which are responsible for autosomal and X-linked Alport syndrome. PAX2 mutations may result in abnormal GBM structure.

An analysis of five clear cell papillary cystadenomas of mesosalpinx and broad ligament: four associated with von Hippel‐Lindau disease and one aggressive sporadic type

Clear cell papillary cystadenoma (CCPC) is associated with von Hippel-Lindau disease (VHLD), but rarely involves mesosalpinx and broad ligament (M/BL). This study provides new data about its behaviour and immunophenotype. We performed an analysis of four benign cases of CCPC of M/BL with either characteristic clinical features or genetic markers [loss of heterozygosity (LOH)] of VHLD in patients ranging from 24 to 36 years and a sporadic case in a 52-year-old presenting with peritoneal metastases. All CCPCs were papillary but had solid and tubular areas. Haemorrhage, thrombosis and scarring were constant features and related to an unusual pattern of sub-epithelial vascularity. All clear or oxyphilic cells co-expressed cytokeratin 7 (CK7), CAM5.2 and vimentin, with strong apical CD10 and nuclear paired box gene 2 (PAX2) immunoreactivity. Three cases also showed positivity for VHL40, epithelial membrane antigen (EMA), Wilms' tumour suppressor gene (WT-1) and cancer antigen 125 (CA125) but only one expressed renal cell carcinoma (RCC) antigen. Vascular plexus overexpressed nuclear and cytoplasmic WT-1. The VHLD-associated cases appeared to be benign, but the sporadic case exhibited a low malignant potential. CCPCs show histological and immunophenotypical similarities with the recently reported clear cell papillary RCC, although the previously unreported apical CD10 and nuclear PAX2 expression may be related to their mesonephric origin. CCPC has a distinctive sub-epithelial vascular pattern that is consistent with its pathogenesis.

VHL mutations and dysregulation of pVHL- and PTEN-controlled pathways in multilocular cystic renal cell carcinoma

Multilocular cystic renal cell carcinoma is a rare renal cell carcinoma with an excellent prognosis. To clarify the relationship with typical clear cell renal cell carcinoma, we evaluated 15 cases of multilocular cystic renal cell carcinomas diagnosed according to the 2004 WHO classification. Von Hippel Lindau (VHL) gene mutations were determined by whole genome amplification and direct sequencing. Carbonic anhydrase 9 (CAIX), a hypoxia-inducible factor (HIF) target, paired box gene 2 (PAX2), cyclin-dependent kinase inhibitor p27 and glycogen synthase kinase 3-β (GSK3β) were immunohistochemically evaluated as members of the VHL protein (pVHL)- and phosphatase and tensin homolog (PTEN)-controlled pathways. VHL mutations were identified in 3 of 12 (25%) tumors. Inactivated GSK3β, decreased PTEN expression and PAX2 positivity were observed in the vast majority of the multilocular cystic renal cell carcinomas. Strong nuclear staining of p27 was seen in 14 of 15 cases. Compared with multilocular cystic renal cell carcinomas, expression frequencies of PAX2, p-GSK3β, PTEN and CAIX were similar in a set of low-grade, early-stage clear cell renal cell carcinomas, whereas only 30% had strong p27 positivity. These results are consistent with the hypothesis that multilocular cystic renal cell carcinomas are related at the molecular level with clear cell renal cell carcinomas. Maintenance of a strong subcellular p27 expression in all multilocular cystic renal cell carcinomas analyzed may in part explain the excellent prognosis of these tumor patients.