Imprinted H19 gene expression in embryogenesis and human cancer: the oncofetal connection

Cancer cells resemble embryonal cells morphologically and share with them characteristics such as reduced differentiation, rapid proliferation rate, and increased motility. Genes expressed in embryogenesis, down-regulated with tissue maturation and reexpressed in cancer, are designated as oncofetal genes, and many of them are used as tumor markers. The H19 gene is an imprinted gene that is expressed from the maternal allele and functions as an RNA molecule. It is abundantly expressed in fetal life and down-regulated postnatally. We have shown oncofetal expression of H19 in human cancer. The study of H19 expression in testicular germ cell tumors of adolescents and young adults, which follow lines of differentiation of the conceptus, demonstrates dissociation between level of expression and monoallelic versus biallelic expression, which are two independent oncofetal characteristics of cancer. Expression of the maternally expressed H19 from the paternal allele in the villous cytotrophoblastic cells of the androgenetic complete hydatidiform mole is designated relaxation of imprinting. H19 is abundantly expressed in the fetal bladder mucosa and in carcinoma of the urinary bladder. It is a marker of early recurrence and may be used as a potential basis for gene therapy.

Synaptogenesis and myopathy under acetylcholinesterase overexpression

Environmental, congenital, and acquired immunological insults perturbing neuromuscular junction (NMJ) activity may induce a variety of debilitating neuromuscular pathologies. However, the molecular elements linking NMJ dysfunction to long-term myopathies are unknown. Here, we report dramatically elevated levels of mRNA encoding c-Fos and the "readthrough" (R) variant of acetylcholinesterase (AChE) in muscles of transgenic mice overexpressing synaptic (S) AChE in motoneurons and in control mice treated with the irreversible cholinesterase inhibitor diisopropylfluorophosphonate (DFP). Tongue muscles from DFP-treated and AChE-S transgenic mice displayed exaggerated neurite branching and disorganized, wasting fibers. Moreover, diaphragm muscles from both transgenic and DFP-treated mice exhibited NMJ proliferation. 2'-O-methyl-protected antisense oligonucleotides targeted to AChE mRNA suppressed feedback upregulation of AChE and ameliorated DFP-induced NMJ proliferation. Our findings demonstrate common transcriptional responses to cholinergic NMJ stress of diverse origin, and implicate deregulated AChE expression in excessive neurite outgrowth, uncontrolled synaptogenesis, and myopathology.

Tie-2 and angiopoietin-2 expression at the fetal-maternal interface: a receptor ligand model for vascular remodelling

The blood vessels at the fetal-maternal interface widen dramatically during pregnancy in order to increase blood flow to nourish the developing fetus. This vessel remodelling destroys normal vessel integrity and encompasses the dissolution of vessel muscle and elastic tissue. It also includes the displacement of endothelial cells by fetal trophoblasts that invade the maternal arteries of the uterus. Interaction between the endothelial cell receptor, Tie-2, and its recently discovered antagonist ligand, angiopoietin-2 (Ang-2), has been implicated in the loosening of vessel structure. Using Northern blot hybridization and RNA in-situ hybridization analysis the expression pattern of Tie-2, and Ang-2 in the placenta throughout pregnancy, was investigated. We found Ang-2 expressed in the syncytiotrophoblast during the first trimester. In addition to the expected expression of the Tie-2 receptor in both fetal and maternal endothelial cells, we observed Tie-2 expression in endovascular invasive trophoblasts. These cells of epithelial origin invade the uterine spiral arteries and acquire endothelial cell properties. The temporal- and lineage-specific pattern of expression of Tie-2 and Ang-2 suggests that this receptor-ligand pair functions during the critical phase of development of the fetal vasculature and reworking of the maternal vessels during normal placentation.

Lack of human leukocyte antigen-G expression in extravillous trophoblasts is associated with pre-eclampsia

Pre-eclampsia, a common complication of first pregnancies, is thought to result from a poorly perfused placenta and may reflect an abnormal maternal immune reaction to the hemiallogenic fetus. Human leukocyte antigen (HLA)-G, a major histocompatibility tissue-specific antigen expressed in extravillous trophoblast cells (fetal-derived), may protect trophoblasts from maternal-fetal immune intolerance and allow these cells to invade the uterus. Through RNA in-situ hybridization analysis, we studied the expression pattern of HLA-G in normal placentae and placentae from pregnancies complicated by severe pre-eclampsia. In normal placenta we found HLA-G expression in the anchoring extravillous trophoblasts with an increasing gradient of expression in the more invasive cells. However, in nine out of 10 pre-eclamptic placentae HLA-G expression was absent or reduced. We conclude that HLA-G is normally expressed in invasive trophoblasts and HLA-G expression is defective in most pre-eclamptic placentae. We propose that trophoblasts lacking HLA-G are vulnerable to attack by the maternal immune system. These defective trophoblasts will be unable to invade the maternal spiral arteries effectively, thereby developing vessels which cannot adequately nourish the developing placenta. This poorly perfused placenta may initiate the systemic cascade of events associated with pre-eclampsia.

Inhibition of bladder carcinoma angiogenesis, stromal support, and tumor growth by halofuginone

We have previously demonstrated that halofuginone, a widely used alkaloid coccidiostat, is a potent inhibitor of collagen alpha1(I) and matrix metalloproteinase 2 gene expression. Halofuginone also suppresses extracellular matrix deposition and cell proliferation. We investigated the effect of halofuginone on transplantable and chemically induced mouse bladder carcinoma. In both systems, oral administration of halofuginone resulted in a profound anticancerous effect, even when the treatment was initiated at advanced stages of tumor development. Although halofuginone failed to prevent proliferative preneoplastic alterations in the bladder epithelium, it inhibited further progression of the chemically induced tumor into a malignant invasive stage. Histological examination and in situ analysis of the tumor tissue revealed a marked decrease in blood vessel density and in both collagen alpha1(I) and H19 gene expression. H19 is regarded as an early marker of bladder carcinoma. The antiangiogenic effect of halofuginone was also demonstrated by inhibition of microvessel formation in vitro. We attribute the profound antitumoral effect of halofuginone to its combined inhibition of the tumor stromal support, vascularization, invasiveness, and cell proliferation.

Expression of the imprinted H19 oncofetal RNA in epithelial ovarian cancer

STUDY

To examine the expression of the imprinted maternally expressed H19 gene in benign, low malignant potential (borderline) and malignant surface epithelial ovarian tumors.

DESIGN

In situ hybridization for H19 RNA using S-labeled and digoxigenin-labeled probes was performed on paraffin sections of ovarian surface epithelial tumors. The serous tumors included nine section cystadenomas, twelve serous tumors of low malignant potential and twenty serous carcinomas, grade I-IIII (FIGO classification). A smaller group included two mucinous cystadenomas, four mucinous tumors of low malignant potential and two mucinous cystadenocarcinomas.

RESULTS

H19 expression was found to be positive in 6/9 (67%) serous cystadenomas, 9/12 (75%) of serous tumors of low malignant potential and 13/20 (65%) of invasive serous carcinomas. Expression in mucinous tumors was confined to the stroma beneath the epithelial lining.

CONCLUSION

H19 is expressed in the majority of serous epithelial tumors. Taking into consideration the high percentage of H19 expressing serous ovarian neoplasms we suggest that H19 RNA may be used as an adjuvant tumor marker for the diagnosis and mainly for staging and follow-up of patients with serous ovarian carcinoma.

High levels of maternal serum human chorionic gonadotropin in Down syndrome pregnancies: the possible role of a transcription factor on chromosome 21

Increased levels of human chorionic gonadotropin (hCG) are used as markers for Down syndrome (DS) screening of low-risk populations. The pathophysiology for increased hCG levels remains unknown. In general, hCG synthesis is limited by the rate of beta-chain formation. In the placenta, 2 of a total of 6 hCG beta-genes are expressed. We hypothesized that in DS, a transcriptional factor may upregulate beta-chain transcription by interacting with the beta5-promoter. Primary cell cultures of skin fibroblasts from both normal and DS midtrimester fetuses were established and transfected with the beta5-promoter linked to the chloramphenicol-acetyl-transferase reporter gene. The chloramphenicol-acetyl-transferase activity was measured. Three of six DS-derived cell cultures showed a three-fold increase in acetylation. The increase in hCG promoter activity in DS-derived fibroblasts suggests a possible role for a transcriptional factor located on the human chromosome 21 by either directly or indirectly interacting with the beta5-promoter.

The dynamics of the imprinted H19 gene expression in the mouse model of bladder carcinoma induced by N-butyl-N-(4-hydroxybutyl)nitrosamine

The imprinted H19 gene product is an oncofetal RNA molecule in humans. It is expressed in fetal bladder, down-regulated postnatally and is re-expressed in human bladder carcinoma. This study was designed to investigate the dynamics of the expression of H19 in the mouse bladder carcinoma induced by N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN) and its relation to stages of neoplastic transformation. BBN was administered to mice in the drinking water for 26-28 weeks. The bladders were removed at 5-10 week intervals for histopathological examination and for in situ hybridization for H19 RNA, using a 35S-labeled probe. Following BBN administration expression of H19 first appeared after 5 weeks in the lamina propria adjacent to the basement membrane, concomitant with mucosal hyperplasia. At 11 weeks focal expression was noted in epithelial cells. Invasive carcinomas, of the transitional and squamous sub-types, were seen after 20 weeks and more of BBN administration. At this stage H19 expression was observed in scattered tumor cells, in the connective tissue stroma of the tumor and in the lamina propria underlying the remaining hyperplastic/dysplastic mucosa. Abundant expression of H19 was evident in fetal bladder but was absent in normal adult bladder. We conclude that, similar to humans, the H19 gene product is an oncofetal RNA molecule in the experimental mouse model of bladder carcinoma. In this model H19 is expressed in the connective tissue of the lamina propria prior to its expression in epithelial cells, concurrent with preneoplastic changes in the transitional epithelium of the bladder.

Prenatal sonographic appearance of congenital fibrosarcoma

Congenital fibrosarcoma is a rare soft tissue sarcoma. A 22-year-old woman in the 22nd week of her first pregnancy underwent sonographic examination, which revealed a soft tissue swelling of the fetus's left thigh. The pregnancy was terminated, and congenital fibrosarcoma was diagnosed by pathologic examination. To our knowledge, this is the first published report of the intrauterine sonographic observation of this tumor in a fetal extremity.

Endothelial nitric oxide synthase immunoreactivity in early gestation and in trophoblastic disease

AIMS

To study the localisation of the endothelial nitric oxide synthase (eNOS) in the normal placenta, with special emphasis on the implantation site in the first trimester of pregnancy, and in the different subtypes of trophoblastic cells in gestational trophoblastic disease.

METHODS

The immunoperoxidase technique with an antibody directed against eNOS was applied to paraffin sections from first and second trimester placentas, placenta accreta, partial and complete hydatidiform moles, and choriocarcinoma. Immunoperoxidase staining for human placental lactogen (hPL) was performed on parallel sections.

RESULTS

Prominent immunoreactivity for eNOS was found to be present in the intermediate trophoblastic cells of the cell columns of the anchoring villi and in trophoblastic cells at the implantation site. Staining was also present in the syncytiotrophoblast, most conspicuous at the apical cell border. In trophoblastic disease, proliferating large mononuclear cells, which were strongly positive for hPL, were found to be immunoreactive for eNOS.

CONCLUSIONS

eNOS immunoreactivity is strongly positive in the extravillous trophoblastic cells and to a lesser extent in the syncytiotrophoblast. In the former it may play a role in implantation and vascular invasion. Cells with differentiation to intermediate trophoblast in complete hydatidiform mole and choriocarcinoma also show high levels of eNOS, which may be associated with the haematogenous mode of spread of trophoblastic disease.

Imprinted H19 oncofetal RNA is a candidate tumour marker for hepatocellular carcinoma

AIMS/BACKGROUND

To study the expression of the H19 gene in hepatocellular carcinoma. H19 is an imprinted, maternally expressed gene, which is tightly linked, both physically and functionally, to the paternally expressed insulin-like growth factor 2 (IGF II). IGF II is known to be involved in liver carcinogenesis. H19 was first discovered in the fetal mouse liver to be under the same regulatory genes as alpha fetoprotein (alpha FP), a widely used tumour marker for hepatocellular carcinoma.

METHODS

Using both radioactive and non-radioactive in situ hybridisation, the expression of the H19 gene was compared with the presence of alpha FP, as demonstrated by immunohistochemistry, in 18 cases of hepatocellular carcinoma.

RESULTS

H19 expression was present in 13 of 18 cases, whereas staining for alpha FP was positive in only nine of 18 cases. Concordance was found in 12 of 18 tumours (66.7%). In general, the staining pattern for H19 was more diffuse than the immunohistochemical staining for alpha FP.

CONCLUSIONS

The addition of a non-radioactive in situ hybridisation assay for H19 RNA to the panel of tumour markers used for the histopathological and cytological diagnosis of hepatocellular carcinoma might be useful.

The role of midtrimester targeted fetal organ screening combined with the "triple test" and maternal age in the diagnosis of trisomy 21: a retrospective study

OBJECTIVE

Our purpose was to evaluate the role of fetal ultrasonography in prenatal detection of trisomy 21.

STUDY DESIGN

A retrospective study was performed on all cases of trisomy 21 diagnosed prenatally or postnatally between January 1990 and December 1993 in the Jerusalem metropolitan area. Our program of prenatal detection of trisomy 21 is a three-tiered, chronologically progressive screening that includes maternal age, biochemical serum markers, and targeted fetal organ survey. Sixty-seven thousand ninety-two babies were born during the study period; 17,084 maternal biochemistry analyses (triple test) were performed; and 6315 fetuses were karyotyped.

RESULTS

One hundred eight cases of trisomy 21 were diagnosed prenatally and postnatally. The overall rate of detection of trisomy 21 was 92.2% when our recommendations were followed. Among those cases diagnosed prenatally, 66.6% of trisomy 21 cases had been referred for fetal karyotyping because of maternal age > or = 35 years, 18.5% because of abnormal triple test results, and 11.1% because of fetal ultrasonographic findings associated with trisomy 21. Among women < 35 years old, 80% of trisomy 21 cases were detected prenatally. Of these, 50% had been referred for karyotyping because of triple test results and 30% because of abnormal ultrasonographic findings.

CONCLUSION

Midtrimester ultrasonographic targeted fetal organ screening plays a critical role in prenatal diagnosis of trisomy 21 among women under the age of 35 years.

Infantile hemangioendothelioma of the ovary: a monodermal teratoma or a neoplasm of ovarian somatic cells?

Vascular tumors of the female genital tract are uncommon, and only a few cases have been reported in the ovary. We describe herein, an unusual tumor of the ovary: infantile hemangioendothelioma (cellular hemangioma of infancy) in a newborn. The tumor consisted of well-formed blood vessels and proliferating endothelial cells that were arranged in solid cordlike structures. The tumor permeated the ovarian stroma and entrapped normal ovarian follicles. By immunohistochemistry the neoplastic cells expressed factor VIII, CD34, and alpha smooth-muscle actin, and ultrastructurally they had the features of endothelial cells that were focally associated with pericytes. We examined simple sequence repeat (SSR) polymorphic markers in the tumor tissue, as well as in the patient's and parents' blood. The informative SSR markers were found to be identical in the tumor and in the patient's somatic cells. We suggest that the tumor described herein is a congenital infantile hemangioendothelioma arising from ovarian parenchymal cells rather than a teratoma originating from germ cells. A similar morphologic lesion has been described recently in the ovary and interpreted as monodermal teratoma composed of vascular tissue.

Frequent apoptosis in human kidneys after acute renal hypoperfusion

BACKGROUND/AIMS

Apoptosis, a form of cell death characterized by DNA fragmentation and minimal inflammation, is induced by intrarenal hypoxia in rats. The objective of this study was to test whether apoptosis participates in human acute renal injury.

METHODS

We examined kidneys obtained from autopsies of 40 patients following hemodynamic compromise and from 9 controls following sudden death. Nuclear DNA fragmentation was assayed by in situ 3' end labeling (TUNEL stain) and compared to histological findings.

RESULTS

DNA fragmentation along renal tubular cells was observed in 23 (57%) of the study patients but in none of the controls (p < 0.005). Acute tubular necrosis was seen by formal histology in 27% of the patients and correlated with clinical acute renal dysfunction, while DNA fragmentation did not.

CONCLUSION

DNA fragmentation often occurs after renal hypoperfusion and does not imply renal failure. Apoptosis may participate in the adaptive response of the kidney to hypoxia.

Genomic imprinting and the endometrial cycle. The expression of the imprinted gene H19 in the human female reproductive organs

H19 is an imprinted maternally expressed gene, which is not translated to protein and functions as an RNA molecule. It is closely related to the oppositely imprinted paternally expressed insulin-like growth factor 2 (IGF-2). While the biological function of H19 is not understood IGF-2 is a growth factor that plays a role in human follicular and endometrial differentiation. We examined the expression of H19 in the endometrium and ovary during the menstrual cycle by in situ hybridization applied to paraffin sections of human endometrium and ovaries at different stages of differentiation. In the endometrium, H19 expression was confined to the stroma and fluctuated with endometrial dating to reach its peak in the late secretory stage. IGF-2 was also prominently expressed in late secretory endometrium, but its expression was evident both in the stroma and glandular epithelium. Expression of H19 was not found in primordial, primary, and preantral follicles of the ovary, but prominent expression was evident in the theca of antral and cystic atretic follicles, and focal expression was noted in the granulosa of corpora lutea. An association between H19 expression during the menstrual cycle and the differentiation state of the human female reproductive tract, which is under hormonal control, is suggested.

Trisomy 2: confined placental mosaicism in a fetus with intrauterine growth retardation

In a pregnancy that was monitored due to increased risk for Down syndrome in the triple test, a normal karyotype was found in amniocentesis. Follow-up by serial ultrasound examinations revealed intrauterine growth retardation (IUGR) at 20 weeks of gestation. The parents decided to terminate the pregnancy and the karyotype of the placental fibroblasts was 47,XX,+2. Analysis of polymorphic markers of chromosome 2 demonstrated (a) that trisomy 2 was confined to the placenta (CPM), (b) that the trisomy 2 cell line was a result of a meiotic I error of paternal origin, and (c) that the fetal tissues with a normal karyotype were biparental disomy 2.

The product of the imprinted H19 gene is an oncofetal RNA

AIMS/BACKGROUND

The H19 gene is an imprinted, maternally expressed gene in humans. It is tightly linked and coregulated with the imprinted, paternally expressed gene of insulin-like growth factor 2. The H19 gene product is not translated into protein and functions as an RNA molecule. Although its role has been investigated for more than a decade, its biological function is still not understood fully. H19 is abundantly expressed in many tissues from early stages of embryogenesis through fetal life, and is down regulated postnatally. It is also expressed in certain childhood and adult tumours. This study was designed to screen the expression of H19 in human cancer and its relation to the expression of H19 in the fetus.

METHODS

Using in situ hybridisation with a [35S] labelled probe, H19 mRNA was detected in paraffin wax sections of fetal tissues from the first and second trimesters of pregnancy and of a large array of human adult and childhood tumours arising from these tissues.

RESULTS

The H19 gene is expressed in tumours arising from tissues which express this gene in fetal life. Its expression in the fetus and in cancer is closely linked with tissue differentiation.

CONCLUSIONS

Based on these and previous data, H19 is neither a tumour suppressor gene nor an oncogene. Its product is an oncofetal RNA. The potential use of this RNA as a tumour marker should be evaluated.

Unique expression patterns of H19 in human testicular cancers of different etiology

The expression pattern of the imprinted human H19 gene was investigated in testicular cancers of different etiology, as well as in normal testicular parenchyma, parenchyma without germ cells, and adjacent to testicular germ cell tumors of adolescents and adults (TGCTs), using RNase protection analysis, mRNA in situ hybridization and reverse-transcription polymerase chain reaction. While different total expression levels were detected in spermatocytic seminomas, lymphomas, a Sertoli cell tumor and Leydig cell tumors, none showed a disturbance of monoallelic expression. Strikingly, the majority of invasive TGCTs revealed expression of both parental alleles. The total level of expression highly correlated with differentiation lineage and stage of maturation, similar to that as reported during early normal embryogenesis. Biallelic expression could also be determined specifically in testis parenchyma containing the preinvasive lesion of this cancer. We therefore conclude that within the adult testis, biallelic H19 expression is specific for TGCTs, and that the level of expression is dependent on differentiation lineage and maturation stage. This is in agreement with the proposed primordial germ cell-origin of this cancer, and might be related to retention of embryonic characteristics in TGCTs. In addition, our data argue against H19 being a tumor suppressor gene.

Renal pathology in WAGR syndrome

The Wilms' tumor-aniridia-genital anomalies-mental retardation (WAGR) syndrome is associated with an increased risk for developing Wilms' tumor. A right nephrectomy was performed following the diagnosis of Wilms' tumor in a 2-year-old girl with WAGR syndrome and chromosome 11, del 11p13. Pathologic examination revealed intralobar nephrogenic rests and a peripelvic multicystic mass, sharply delineated from the adjacent typical intralobar nephrogenic rests and renal parenchyma, which may represent a cystic Wilms' tumor (cystic partially differentiated nephroblastoma). We studied the expression of the H19 gene by in-situ hybridization performed on paraffin sections of the kidney. H19 is an imprinted maternally-expressed gene that is not translated to protein and functions as a regulatory RNA molecule. It is tightly linked with the paternally-imprinted gene of insulin-like growth factor 2. While IGF2 presumably plays a role in tumorigenesis of Wilms' tumor, H19 is not expressed in the majority of Wilms' tumors. The expression of H19 in the intralobar nephrogenic rests was found to be prominent in the component of the blastema and markedly reduced with differentiation to tubular structures similar to the fetal kidney. The differential diagnosis of hyperplastic intralobar nephrogenic rests from a small Wilms' tumor arising in intralobar nephrogenic rests is difficult. Complete understanding of the chain of molecular events occurring in the evolution of Wilms' tumors may lead to the development of tumor markers to be used on paraffin sections and so help in the differential diagnosis of hyperplasia versus malignant transformation.

Hyaluronan, CD44 and its variant exons in human trophoblast invasion and placental angiogenesis

Both hyaluronan and one of its receptors, CD44, can be demonstrated in the early human conceptus and in placental stroma. The variants of CD44 resulting from variable exon splicing are found in metastasizing human malignancies and are also involved in hyaluronan uptake and degradation. The resulting hyaluronan fragments are known to be highly angiogenic. We postulated that the self-limited process of trophoblast invasion of the uterine decidua results in part from the strategy of alternative splicing of CD44, similar to that used by invasive cancer cells in the course of metastatic spread and possibly angiogenesis. Monoclonal antibodies specific for CD44s and for an exon expressed during metastatic tumour progression, CD44v7, were used to examine this hypothesis. In this study we found human trophoblasts, for the first time, to express CD44. Intermediate trophoblasts of first and second trimester exhibited the standard form of CD44 while extravillous trophoblasts, which are responsible for the invading characteristics of the placenta, were positive for the alternatively spliced form, the CD44v7-8. Moreover, in the case of placenta accreta there was a prominent membrane staining of the trophoblasts that were embedded in the fibrin layer over the myometrium. The highly metastatic choriocarcinoma cells also expressed CD44v7-8. We propose, therefore, that the invading trophoblasts utilize the alternatively splicing machinery. These cells retain their invasive capabilities through the permissive ECM by carrying the CD44v7-8 isoform, which binds weakly to hyaluronan and thus prevents it from being degraded by intracellular hyaluronidase.

Developmentally imprinted genes as markers for bladder tumor progression

PURPOSE

Developmentally imprinted genes, such as H19 and insulin-like growth factor-II (IGF-II), play an important role during human embryogenesis and also have been implicated in the pathogenesis of embryonal tumors of childhood. Since H19 is expressed in human fetal bladder, we evaluated 35 bladder carcinomas for H19 expression by in situ hybridization analysis and correlated expression with tumor grade. As a prelude to gene transfer studies to determine if H19 is a bladder tumor oncogene, we also evaluated bladder cell lines for expression of H19, IGF-II, IGF-I and the type I IGF receptor.

MATERIALS AND METHODS

H19 expression was evaluated by in situ hybridization analysis in bladder tumor specimens. Northern analysis was used to evaluate the expression of H19, IGF-II, IGF-I and the type I IGF receptor in bladder cell lines.

RESULTS

H19 was expressed preferentially in advanced stage tumors: 2 of 12 grade I tumors were H19 positive, whereas 9 of 11 grade II and 7 of 10 grade III tumors expressed H19 (p = 0.004). Additionally, 6 of 6 carcinoma in situ tumors were H19 positive, whereas normal bladder mucosa cells were H19 negative. We found that 3 of 11 cell lines (HT-1376, HT-1197 and 5637) express high levels of H19 mRNA, and each of these cell lines and J82 also express IGF-II. All cell lines examined expressed the type I IGF receptor, whereas there was no detectable IGF-I mRNA.

CONCLUSIONS

These data demonstrate that H19 is an oncodevelopmental marker of bladder tumor progression and raise the possibility that H19 may have oncogenic properties in bladder cancer.

Thomas syndrome: potter sequence with cleft lip/palate and cardiac anomalies

Holzgreve et al. [Am J Med Genet 18:177-184, 1984] first reported on a syndrome including renal anomalies, heart defect, polydactyly, and cleft palate with other oropharyngeal anomalies. We report here on four sibs with renal adysplasia associated in two with cardiovascular malformations and cleft lip or cleft palate in two. We propose that these patients as the two siblings reported by Thomas et al. [Am J Med Genet 45:767-769, 1993] are affected with a syndrome different of the one described by Holzgreve et al. [Am J Med Genet 18:177-184, 1984] mainly because of the absence of polydactyly. Thomas syndrome is probably inherited as an autosomal recessive trait with marked variability.

Familial renal tubular dysgenesis: a disorder not isolated to proximal convoluted tubules

The autopsy findings of a newborn with renal tubular dysgenesis, born to first cousins of Moslim Arab descent, are described. Hypocalvaria and hyperflexible joints were noted in addition to the renal lesion. A microdissection study demonstrated marked shortening of all the nephron segments from the glomeruli to the collecting tubules, rather than an isolated abnormality of the proximal convoluted tubules.