Altered phosphorylation state of branched-chain 2-Oxo acid dehydrogenase in a branched-chain acyltransferase deficient human fibroblast cell line

Summary The abundance and phosphorylation state of the polypeptide constitutents of the human branched-chain 2-oxo acid dehydrogenase complex were examined in mitochondria from normal and maple syrup urine disease (MSUD) fibroblasts. In normal fibroblast mitochondria two forms of the E₁ subunit were observed: non-phosphorylated (E₁) and phosphorylated (E_1–P). About 40–50% of E₁ was present as E_1–P. The ability to quantitate the two forms of E₁ permitted examination of the association between decreased capacity to oxidize branched-chain 2-oxo acids and the phosphorylation state of E₁.Changes in phosphorylation state of E₁ were observed in MSUD fibroblasts as compared to control cells. Of particular interest was the absence of E_1–P in an MSUD fibroblast line which lacked the dihydrolipoyl acyltransferase (E₂) subunit of the dehydrogenase complex. In two MSUD cell lines deficient in E₁, the abundance of E_1–P appeared to be preferentially reduced. A fourth MSUD cell line contained normal quantities of E₃, E₂ and both forms of the E₁ polypeptide. Our results indicate that alterations in the abundance of dehydrogenase complex polypeptides in MSUD fibroblasts may influence the phosphorylation state of the E₁ polypeptide. They demonstrate the potential for examining simultaneously mutations which affect both the catalytic and regulatory components of the dehydrogenase complex.     

Maple syrup urine disease (MSUD): Screening for known mutations in Italian patients

Summary Maple syrup urine disease (MSUD) is an autosomal recessive disease due to deficiency of the branched-chain -ketoacid dehydrogenase (BCKDH) caused by a large number of mutations. In the present study, DNA from Italian patients and their relatives was examined for three point mutations (Y393N in the E₁ gene, T841G and G1031A in the E₂ gene) and two deletions (–G at the intron/exon border of exon 8 in the E₂ gene and an 11 bp deletion in exon 1 of the E₁ gene) using the polymerase chain reaction (PCR) followed by allele-specific oligonucleotide (ASO) hybridization, gene-scanning size analysis of fluorescent-tagged PCR products and/or automated DNA sequence analysis. Our results show that two different mutations account for 7 of the 20 mutant MSUD alleles. Two unrelated affected children, two of their parents and one sibling were carriers for the 11 bp deletion in the E₁ gene, one patient and her mother were heterozygous for Y393N in E₁, while T841G, G1031A and the –G deletion in E₂ were not detected. This study is the first attempt to characterize at a nucleic acid level MSUD mutations in Italy. Our results indicate that additional defects are present in the Italian population and that, unlike the Mennonites, a number of different MSUD mutations exist in Italians.     

Gene analysis of mennonite maple syrup urine disease kindred using primer-specified restriction map modification

Summary Maple syrup urine disease (MSUD) is an autosomal recessive inherited disease due to a deficiency of any of the subunits, E₁, E₁ or E₂, of the branched-chain -ketoacid dehydrogenase complex (BCKDH). A large Mennonite kindred of MSUD has been studied in Pennsylvania, USA. In the present investigation, genomes from 70 members, including 12 patients belonging to eight different Mennonite MSUD pedigrees, were examined for possible abnormalities in the E₁ gene of BCKDH, by primer-specified restriction map modification. A T-to-A substitution which generates an asparagine in place of a tyrosine at amino acid 394 of the mature E₁ subunit was present in both alleles in all the patients and in a single allele in all obligate carriers and several siblings. We describe a new technique for rapid and easy detection of the mutant gene in this population. These family studies provide additional evidence that Mennonite MSUD is caused by a missense mutation of the E₁ gene of BCKDH.     

X-linked pyruvate dehydrogenase E1α subunit deficiency in heterozygous females: Variable manifestation of the same mutation

Summary Three female patients are described with pyruvate dehydrogenase (PDH) deficiency as a result of mutation in the X-linked gene for the E1 subunit of the complex. Two of these patients illustrate typical presentations of PDH E1 deficiency, with severe neurological dysfunction, degenerative changes and developmental anomalies in the brain, together with variable lactic acidosis. The third patient extends the known spectrum of the condition to include mild to moderate mental retardation and seizures in an adult. All three patients have the same mutation in the PDH E1 gene. This mutation, a C-to-T substitution in a CpG dinucleotide in amino acid codon 302 (designated R302C), results in the replacement of arginine by cysteine at this position. The mildly affected adult was the mother of one of the other patients, making this the first described instance of mother-to-daughter transmission of a mutation causing PDH E1 deficiency. The genetic basis of the variable expression of X-linked PDH E1 deficiency in heterozygous females is discussed.     

Identification and characterization of novel mutations of the aspartoacylase gene in non-Jewish patients with Canavan disease

Canavan disease, an inherited leukodystrophy, is caused by mutationsin the aspartoacylase (ASPA) gene. It is most common among children of Ashkenazi Jewish descent but has been diagnosed in many diverse ethnic groups.Two mutations comprise the majority of mutant alleles in Jewish patients, while mutations in the ASPA gene among non-Jewish patients are different and more diverse. In the present study, the ASPA gene was analysed in 22 unrelated non-Jewish patients with Canavan disease, and 24 different mutations were found. Of these, 14 are novel, including five missense mutations (E24G, D68A, D249V, C152W, H244R), two nonsense mutations (Q184X, E214X), three deletions (923delT, 33del13, 244delA), one insertion mutation (698insC), two sequence variations in one allele ([10T>G; 11insG]), an elimination of the stop codon (941A>G, TAGTGG, X314W), and one splice acceptor site mutation (IVS1–2A>T). The E24G mutation resulted in substitution of an invariable amino acid residue (Glu) in the first esterase catalytic domain consensus sequence. The IVS1–2A>T mutation caused the retention of 40 nucleotides of intron 1 upstream of exon 2. The results of transient expression of the mutant ASPA cDNA containing these mutations in COS-7 cells and assays for ASPA activity of patient fibroblasts indicated that these mutations were responsible for the enzyme deficiency. In addition, patients with the novel D249V mutation manifested clinically at birth and died early. Also, patients with certain other novel mutations, including C152W, E214X, X314W, and frameshift mutations in both alleles, developed clinical manifestations at an earlier age than in classical Canavan disease.     

Rapid detection of −α 4.2 deletion of α-thalassemia-2 by polymerase chain reaction

Summary We sequenced part of the X boxes of-thalassemia-1 of Southeast Asia type (- -SEA) with– ^4.2,– ^3.7,– ^G-Taichung, and ^CS. We found the X box of– ^3.7 belonged to the X box of 2 globin gene and the X box of ^cs contained X boxes of both al and2 globin gene, whereas the X box of– ^4.2 and– ^G-Taichung was a hybrid of X boxes of 2 and 1 globin gene. We also found there are two types of– ^4.2 deletion; type 1 is a common type of– ^4.2 deletion and type 2 is linkage to– ^G-Taichung. We used a combination of two methods, the amplification refractory mutation system (ARMS) and the amplified created restriction sites (ACRS), to amplify the hybrids of X boxes specifically. The upstream primer for X box of2 globin gene was designed following the standard ARMS procedure to amplify the X segment of the-globin gene. The downstream primer was designed according to the ACRS method to check the specificity of PCR products. Using this approach, we can diagnose the different types of– ^4.2 deletion. This kind of approach can also be used to amplify the specific region from the cluster of highly homologous genes.     

Thalassemia intermedia: compound heterozygous β∘/β+-thalassemia and co-inherited heterozygous α+-thalassemia

Summary The relative excess of - over -globin chains in the erythroid precursors is the chief pathophysiological factor of homozygous -thalassemia. The clinical picture is usually characterized by a transfusion-dependent dyserythropoietic anemia (thalassemia major). However, some patients present with moderate anemia that does not require regular blood transfusions (thalassemia intermedia). The molecular heterogeneity of -thalassemia mutations and changes of - and -globin gene expression play an important role in modifying the clinical phenotype. We report here on a female Greek patient with homozygous -thalassemia but normal growth and development, excellent exercise tolerance, and no need of blood transfusions. She is thus mildly affected clinically, although there is marked pallor, jaundice, and hepatosplenomegaly. These signs correspond to her marked hypochromic, microcytic anemia with erythroid hyperplasia of the bone marrow. -Globin genotyping shows her to be compound heterozygous for the codon 39 C T -nonsense mutation and for the T C ⁺-mutation at position 6 of the splice consensus at the exon 1/intron 1 junction (CD39 C T/IVS 1–6 T C). -Globin gene mapping demonstrates the presence of a 3.7-kb ⁺-thalassemia deletion on one allele (–^3.7/). Taken together, this study identifies a complex interaction of genetic factors that do not significantly alter the clinical phenotype when present alone but ameliorate the course of homozygous -thalassemia when inherited in combination.Abbreviations Hb hemoglobin - Hct hematocrit - HPFH hereditary persistence of fetal hemoglobin - IVS intervening sequence - MCH mean corpuscular hemoglobin - MCV mean corpuscular volume - PCR polymerase chain reaction     

PBC-AIH overlap syndrome with concomitant ITP and Hashimoto’s disease with positivity for anti-centromere antibody

We report a case of primary biliary cirrhosis (PBC)-autoimmune hepatitis (AIH) overlap syndrome with concurrent idiopathic thrombocytopenic purpura (ITP) and Hashimotos disease with positivity for anticentromere antibody. The patient was a 64-year-old woman with symptoms of jaundice and general fatigue. About 30 years earlier, she had been diagnosed as having ITP and had undergone splenectomy. As part of her present history, she had exhibited liver dysfunction in 1995, during the follow-up of Hashimotos disease, and a liver biopsy led to the diagnosis of PBC. In March 2000, she was admitted to hospital because of general fatigue and jaundice. Blood tests revealed: total protein (TP), 6.6g/dl; -globulin (glb), 35.9%; total bilirubin (T-bil), 9.41mg/dl; direct bilirubin (D-bil), 7.52mg/dl; aspartate aminotransferase (AST), 957U/l; alanine aminotransferase (ALT), 651U/l; alkaline phosphatase (ALP), 595U/l; -guanosine triphosphate (GTP), 129U/l; IgG, 2620mg/dl; IgM, 223mg/dl; hepatitis B surface antigen (HBsAg), negative; anti-hepatitis C virus (HCV), negative; antinuclear antibody, positive; antimitchondrial antibody (AMA), negative (by the immunofluorescence [IF] method); and anti-pyruvate dehydrogenase complex (PDC)-E2 antibody, positive (by Western blotting). Anticentromere antibody (ACA), which is an alternative diagnostic marker for PBC, was detected in this patient. Prednisolone was administered after admission and liver function test results improved markedly. The liver biopsy in 1995 had revealed infiltration of lymphocytes and plasma cells in the portal areas with fibrous expansion and periportal necrosis. Destructive cholangitis was observed, as well as scattered epitheloid cell granulomas in some portal areas. Liver biopsy after the steroid treatment revealed alleviated necrotic inflammatory responses of hepatocytes, while the destructive cholangitis persisted. This is a very rare case of PBC-AIH overlap syndrome accompanied by ITP and Hashimotos disease which provides a possible insight into the mechanisms and interplay of autoimmune diseases.     

Über den sog. Alveolarzellkrebs („Lungenadenomatose”).

Zusammenfassung Auf Grund von 3 neuen Beobachtungen wird gegenüber der auf Indizienbeweisen, Analogieschlüssen und der deductio per exclusionem beruhenden Anschauung bezweifelt, daß das Alveolarzellcarcinom eine selbständige blastomatöse Erkrankung der menschlichen Lunge darstelle. Ein multizentrisches oder holoblastisches Wachstum ist nicht zu beweisen. Dagegen liegen genügend Anhaltspunkte dafür vor, daß das Alveolarzellcarcinom eine besondere Form der Geschwulstmetastasierung bei intra-und extrapulmonalen Krebsen darstellt. Ein Alveolarzellcarcinom im Sinne einer Lungenadenomatose gibt es bis jetzt nach der Meinung des Verfassers nicht. Ob letztere als eine der Lungenadenomatose der Tiere gleichartige Erkrankung auch beim Menschen vorkommt, wird die Zukunft zeigen müssen.Mit 4 Textabbildungen     

Mutation of E1α gene in a female patient with pyruvate dehydrogenase deficiency due to rapid degradation of E1 protein

Summary A mutation of an insertion of 4 bp in the gene for the subunit of pyruvate dehydrogenase (E1) was found in a female with pyruvate dehydrogenase deficiency due to the rapid degradation of and subunit proteins of pyruvate dehydrogenase. This mutation caused a frameshift that altered the amino acid sequence and created a premature stop codon. This 4-bp insertion has been found in an unrelated female patient with E1 deficiency. It is rare that the same mutation is found in unrelated patients with this rare inborn error of metabolism. Furthermore, short deletions or duplications in the E1 gene of patients with E1 deficiency have been found only in exons 10 and 11. These exons may be hot spots for the mutations by the recombinational processes. This patient was heterozygous for the normal and a mutant allele. However, in most of the cultured skin fibroblasts from this patient, the mutant allele was expressed. These observations suggest that the X chromosome containing the normal allele was predominantly inactivated so that she developed lactic acidaemia and neurological abnormalities despite being heterozygous. The mutant subunit protein failed to form a stable structure of pyruvate dehydrogenase, so that both and subunit proteins were degraded rapidly.     

Ca++ activation of ATPase activity,ATP-P1 exchange,and tension in briefly glycerinated heart muscle

Summary In the course of Mg-dependent ATP splitting by heart actomyosin, an energy rich actomyosin-ADP complex is formed, which promotes the incorporation of phosphate³²P into ATP in myofibrils. The rate of this ATP-phosphate exchange reaction depends on the extent of actin-myosin overlap which can be decreased by stretching glycerinated muscle fibres. In heart muscle, the calcium-ion dependence of this reaction is similar to that of the actomyosin ATPase, the tension, and immediate fibre stiffness (which is hookean and which is a measure for the number of myosin cross-bridges attached to and interacting with actin).These findings suggest that calcium increases the amount of contractile actomyosin-ADP complexes. The proportionality between tension and ATPase activity further suggests that the rate-limiting step of the cross-bridge cycle (which determines the molecular turnover number, the Wechselzahl of the ATPase) is only little affected by calcium ions. These ions act by recruiting more bridges rather than by accelerating their reactions.In addition, the depressing effect of inorganic phosphate on the contractile tension and its presumable role in energetic insufficiency will be discussed.

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Ca⁺⁺-Aktivinerug von ATPase-Aktivität, ATP-Phosphat-Austausch und Kontraktionskraft in glycerinextrahierten Herzmuskelfasern

Zusammenfassung Im Verlauf der Mg-aktivierten ATPase-Reaktion des Herzaktomyosins wird ein energiereicher Aktomyosin-ADP-Komplex gebildet, durch den die Inkorporation von³²P-Phosphat in ATP begünstigt wird. Die Rate dieser ATP-Phosphat-Austauschreaktion ist abhängig vom Gradder Aktin-Myosin-Überlappung Im Herzmuskel ist die Ca⁺⁺-Abhängigkeit dieser Reaktion ähnlich derjenigen der Aktomyosin-ATPase-Aktivität, der kontraktilen Spannung und der immediate fibre stiffness, die nachHuxley undSimmons (6) ein Maß für die Anzahl der zu jedem Moment angehefteten Querbrücken darstellt.Die Ergebnisse weisen darauf hin, daß Calciumionen die Konzentration des kontraktilen Aktomyosin-ADP-Komplexes erhöhen. Die Proportionalität zwischen Spannung und ATPase-Aktivität ist ferner ein Indiz dafür, daß der ratenlimitierende Schritt des Querbrückenzyklus (der die Wechselzahl der kontraktilen ATPase bestimmt), nur wenig durch Ca⁺⁺-Ionen beeinflußt wird. Calcium bewirkt eher eine Rekrutierung von Querbrücken als eine Beschleunigung ihrer Reaktion.Zusätzlich wird der hemmende Effekt von anorganischem Phosphat auf die kontraktile Spannung im Zusammenhang mit der Entstehung der energetischen Insuffizienz diskutiert.

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Paper, presented at the Erwin Riesch Symposium, Tübingen, September 26–29, 1976

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With 3 figures and 1 table

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Supported by the Deutsche Forschungsgemeinschaft SFB 90.     

A case of PDH-E1α mosaicism in a male patient with severe metabolic lactic acidosis

We have characterized a novel mutation in a male patient that affects the coding sequence of PDH-E₁ gene and changes arginine-141 to a leucine. This nucleotide substitution was found in about 75% of the studied DNA (fibroblasts, liver and muscle), a scenario that would indicate a case of E₁ mosaicism in a male patient. When the mutant E₁ protein was expressed in human skin fibroblasts with zero endogenous pyruvate dehydrogenase complex activity and E₁ protein expression, no significant restoration of activity was recorded, in contrast to the wild-type cDNA, even though both wild-type and mutant protein levels were comparable. We concluded that the R141L mutation is a severe one and that it must have occurred in one of the E₁ alleles during early embryogenesis.     

Triplication (/ααα<Superscript>Anti3.7</Superscript>) or deletion (-α<Superscript>3.7</Superscript>/) association in Argentinian β-thalassemic carriers

Prevalence of alpha gene triplication or deletion in -thalassemia carriers was studied in 109 unrelated individuals in Rosario, Argentina. In different populations -^3.7 allele presents a higher prevalence than ^anti3.7; thus, -thalassemia associated with -thalassemia is more frequently observed. Nevertheless, this event was detected in only one case (0.9%), while the association with alpha triplication was present in two subjects (1.8%).     

Hemoglobin E and codon 17 nonsense: Two β-globin gene mutations common in Southeast Asia detected by the use of ARMS

Summary Hemoglobin E (codon 26 GAGAAG) and codon 17 nonsense (AAGTAG), two clinically important mutations of the -globin gene, are common in Southeast Asia. The detection of these mutations using allele-specific PCR is described. Together with the previously reported method for the detection of the common Southeast asian codon 41–42 frameshift mutation (del CTTT), it is possible to identify the vast majority of clinically important -globin gene mutations in Southeast Asian populations by means of nonradioactive methods.This study was supported by theVolkswagen-Stiftung     

α1-antitrypsin deficiency and liver disease

Summary ₁-Antitrypsin (₁AT) deficiency, one of the most common lethal hereditary disorders among Caucasians, is associated with emphysema in adults, while in children it is associated with liver disease. Produced in the liver and released into the plasma, ₁AT serves as the body's major inhibitor of neutrophil elastase, a powerful proteolytic enzyme capable of degrading extracellular structural proteins. The pathogenesis of the liver disease associated with ₁AT deficiency is not as well understood, but is clearly linked to specific mutations in coding exons of the ₁AT gene, and the resulting accumulation of ₁AT within hepatocytes. At present, therapy for the liver disease associated with ₁AT deficiency is symptomatic, with liver transplantation as a last resort. New strategies are being developed to suppress the accumulation of ₁AT by transferring the normal gene into the liver.     

α-Keto Acids Accumulating in Maple Syrup Urine Disease Stimulate Lipid Peroxidation and Reduce Antioxidant Defences in Cerebral Cortex From Young Rats

Maple syrup urine disease (MSUD) is an inherited neurometabolic disorder caused by deficiency of branched-chain -keto acid dehydrogenase complex activity which leads to tissue accumulation of the branched-chain -keto acids (BCKAs) -ketoisocaproic acid (KIC), -ketoisovaleric acid (KIV) and -keto--methylvaleric acid (KMV) and their respective amino acids. Neuropathologic findings characteristic of the disease are cerebral edema and atrophy, whose pathophysiology is poorly known. In the present study, we investigated the in vitro effect of BCKAs on various parameters of oxidative stress, namely chemiluminescence (CL), thiobarbituric acid–reactive substances (TBA-RS), total radical-trapping antioxidant potential (TRAP), total antioxidant reactivity (TAR), and the activities of the antioxidant enzymes catalase (CAT), glutathione peroxidase (GPx), and superoxide dismutase (SOD) in cerebral cortex of 30-day-old rats. The major effects observed were with KIC, which significantly increased CL and TBA-RS measurements, decreased TRAP and TAR values, and markedly inhibited GPx activity. KMV and KIV increased CL and decreased TRAP and TAR values. In contrast, these compounds did not affect CAT and SOD activities. Taken together, it was shown that: the BCKAs studied stimulated lipid peroxidation and reduced the brain antioxidant defences, suggesting an increased production of free radicals. In case the in vitro effects here detected also occur in vivo in MSUD, it can be presumed that oxidative stress might contribute, at least in part, to the brain damage found in the affected patients.     

Distribution of Gs-α activating mutations in human thyroid tumors measured by subcloning

In the search for the prevalence and distribution pattern of Gs- gene mutations in differentiated thyroid tumors we examined 66 tumor tissue samples for the presence of mutations at hot-spot codons 201 and 227 using methods based on the polymerase chain reaction, subcloning and sequencing. the prevailing type of singlebase substitution at codon 201 (71.4%) corresponded to the replacement of the wild-type sequence CGT (Arg) with TGT (Cys). The fragments of the Gs- gene, including codon 201 or 227 from five follicular carcinomas and one follicular adenoma, were subcloned inEscherichia coli and it was found that the proportion of alleles with mutated codon 201 varied from 3.2% to 43%. Sequencing of the corresponding region has confirmed preliminary data indicating that the single-base changes CGT (Arg) to TGT (Cys) or CGT to CAT (His) occurred. There was only a weak correlation between the prevalence of cells bearing a mutation in the Gs- gene and the level of Gs- protein expression in the corresponding thyroid tumors.Abbreviations RFLP restriction-fragment-length polymorphism - MSOH mutation-specific oligonucleotide hybridization - PCR polymerase chain reaction This work was supported by a grant from Deutsche Forschungs-gemeinschaft (Go 356/3-1)     

Transverse myelitis in a patient with Behcet’s disease: favorable outcome with a combination of interferon-α

We report here on a 24-year-old patient with Behçets disease who had been diagnosed with acute transverse myelitis. He was successfully treated with a combination regimen of a steroids, cyclophosphamide, and interferon-. The treatment strategy with specific emphasis on interferon- is discussed in the light of the pertinent literature.     

Enzymatic determination of serum 3α-sulfated bile acids concentration with bile acid 3α-sulfate sulfohydrolase

A newly developed enzymatic method for determining urinary 3-sulfated bile acids was used to measure serum 3-sulfated bile acid levels in 114 patients with hepatobiliary diseases and 56 healthy subjects. The lowest measurable amount of the 3-sulfated bile acids was 0.5 µmol/liter. The standard curves for glycolithocholic acid 3-sulfate, glycoursodeoxycholic acid 3-sulfate, and lithocholic acid 3-sulfate were linear from 0.5 to 250 µmol/liter. Specificity of the assay was satisfactory and intra- and interassay variations ranged from 0.8 to 4.4% and from 1.2 to 7.9%, respectively. Analytical recovery was more than 91%. The values obtained by this assay were well correlated with those by gas-liquid chromatography measurement (r=0.91,P<0.01). The fasting serum 3-sulfated bile acids level in healthy subjects ranged from undetectable to 1.9 µmol/liter (mean±se; 0.9±0.1 µmol/liter). The percentage of 3-sulfated bile acids in total bile acids (sum of 3-sulfated and 3-hydroxy bile acids) in serum was 16.8±1.5%. In subjects with hepatobiliary diseases, serum 3-sulfated bile acids levels were elevated; however, the percentage of 3-sulfated bile acids in total bile acids was decreased and correlated with the severity of hepatocellular insufficiency. This enzymatic assay is simple, rapid, and accurate for the determination of serum 3-sulfated bile acids.     

Expression of growth factors and their receptors in human esophageal carcinomas: regulation of expression by epidermal growth factor and transforming growth factor α

The expression of mRNAs for epidermal growth factor (EGF), transforming growth factor (TGF), EGFR, platet-derived growth factor (PDGF) A and B chain, PDGF receptor (PDGFR), transforming growth factor (TGF),erbB-2 and estrogen receptor (ER) genes was first examined in 6 human esophageal carcinoma cell lines, 6 xenoplanted and 15 surgically resected esophageal carcinomas. Secondly, the effect of EGF and TGF on the expression of these genes by the TE-1 esophageal carcinoma cell line was investigated. The expression of EGF mRNA was detected in 8 (29.6%) of 27 tumors including the cell lines, whereas the TGF and EGFR genes were expressed in 21 (77.8%) and 24 (88.9%) tumors respectively. PDGF B chain and PDGFR were detected in 18 (66.7%) and 20 (74.1%), respectively, and ER mRNA was observed in 16 (59.3%) tumors. Genes for PDGF A chain and TGF and theerbB-2 gene were commonly expressed. On the other hand, exogenous EGF and TGF stimulated the expressions offos andmyc genes by TE-1 cells. The expression of mRNAs for TGF, PDGF A and B chain and theerbB-2 genes was also increased after treatment with EGF. TGF increased the accumulation of mRNAs for EGF, Moreover, the expression of mRNAs for interstitial collagenase, stromelysin and type IV collagenase was increased after EGF or TGF treatment. These results indicate that EGF and TGF may regulate the multi-growth-factor receptor expression and may play a central role for tumor invasion and metastasis as autocrine modulators for human esophageal carcinoma.Abbreviations EGF epidermal growth factor - TGF transforming growth factor - PDGF platelet-derived growth factor - ER estrogen receptor - R receptor