Alpha-fetoprotein Production Research Articles

Factors influencing alpha-fetoprotein (AFP) production by hepatocellular carcinoma (HCC)

Factors influencing alpha-fetoprotein (AFP) production by hepatocellular carcinoma (HCC)

The regulatory role of tri-iodothyronine on the production of alpha-fetoprotein and albumin by mouse fetal liver cells.

The purpose of this study was to assess possible effects of tri-iodothyronine (T3) on the production of alpha fetoprotein (AFP) and albumin by mouse fetal liver cells. AFP from serum-free conditioned media of TIB73 mouse fetal liver cells was measured by immunoradiometric assay and albumin was measured by chromogenic assay. The expression of mRNAs was quantified by Northern blotting analysis. A marked inhibition of AFP secretion was found as well as an increase in albumin produced by T3 in a dose-dependent manner. The effects of T3 AFP and albumin secretion paralleled the effects of T3 on the steady-state expression of mRNAs encoding albumin and AFP. These data may point to a possible role of T3 in the transcriptional switch from AFP to albumin during fetal development and may explain the observation of high levels of AFP in cases of congenital hypothyroidism.

Production of alpha-fetoprotein by human submandibular gland.

Alpha-fetoprotein (AFP) is a 590 amino acid polypeptide that was initially defined as an embryonal serum globulin. The yolk sac endoderm, fetal liver and fetal gut were shown to be the main sites of AFP synthesis in the embryo (Gitlin and Boesman, J. Clin. Invest. 46: 1010-1016, 1967). AFP synthesis is still continued in human adults (Ruoslahti and Seppala, Int. J. Cancer 8: 374-383, 1971) although the physiological level of serum AFP is lower than 10 ng/ml. AFP was also demonstrated in certain tumors and in various diseases or conditions such as yolk sac tumor, hepatoma, hepatoblastoma, acute and chronic liver cirrhosis, pregnancy and so on (Abelev, Adv. Cancer Res. 14: 295-358, 1971; Ruoslahti and Seppala, Cancer Res. 29: 275-346, 1979). Salivary glands have not been implicated in AFP synthesis. We investigated the expression of AFP in normal human salivary glands by immunohistochemistry with a monoclonal antibody against AFP, and documented immunoreactivity in intercalated and striated ducts of adult human submandibular glands.

A Cystic Partially Differentiated Nephroblastoma Producing α-Fetoprotein

A case of cystic partially differentiated nephroblastoma with immunohistochemical and serological demonstration of alpha-fetoprotein (AFP) production is described. To our knowledge, this is the first such case reported. The morphological heterogeneity of this rare tumor led us to describe the criteria of its nosological classification and of its differential diagnosis with intrarenal teratoma. AFP, besides being a marker of germline-derived tumor, was associated to this rare variant of Wilm's tumor. Although the tumor did not show regression either on clinical or pathologic assessments, serum AFP levels decreased after preoperative chemotherapy and returned to normal limits after nephrectomy.

A Cystic Partially Differentiated Nephroblastoma Producing α-Fetoprotein

A case of cystic partially differentiated nephroblastoma with immunohistochemical and serological demonstration of alpha-fetoprotein (AFP) production is described. To our knowledge, this is the first such case reported. The morphological heterogeneity of this rare tumor led us to describe the criteria of its nosological classification and of its differential diagnosis with intrarenal teratoma. AFP, besides being a marker of germline-derived tumor, was associated to this rare variant of Wilm's tumor. Although the tumor did not show regression either on clinical or pathologic assessments, serum AFP levels decreased after preoperative chemotherapy and returned to normal limits after nephrectomy.

Alpha-fetoprotein producing carcinoma of the gallbladder associated with anomalous arrangement of the pancreaticobiliary ductal system—Early detection through an attack of acute pancreatitis

A 56-year-old female was admitted to our hospital with a diagnosis of acute pancreatitis. Ultrasonography revealed a hypoechoic tumor in the gallbladder. The serum alpha-fetoprotein (AFP) level was 971 ng/ml. After healing of the acute pancreatitis, the anomalous arrangement of the pancreaticobiliary ductal system (APDS) was demonstrated by ERCP with mild dilatation of the common bile duct. Within one month after admininon, AFP level reached 4390 ng/ml. On operation, a pedunculated tumor, 6.5 x 3 cm in size, was found in the gallbladder. Histological examination revealed a moderately differentiated adenocarcinoma and positive immunohistochemical staining of cancer cells for AFP. After absolutely curative (stage II) resection, normal serum AFP levels were recognized. This is the first report of an AFP-producing cancer of the gallbladder associated with APDS and it was detected as a result of an attack of acute pancreatitis.

Alpha-fetoprotein production by hepatocellular carcinoma is prognostic of poor patient survival.

Immunohistochemistry using the avidin-biotin-peroxidase complex method was performed to study the production of alpha-fetoprotein (AFP) in hepatocellular carcinoma (HCC) tissue specimens which were obtained surgically. The relationship between staining for AFP and serum AFP levels or pathological findings was examined. The prognosis of the patients with HCC who underwent curative hepatic resections was studied with respect to the staining for AFP in their tumors. The mean serum AFP level in patients with positive AFP staining was significantly higher than in those with negative AFP staining. No significant relationship was found between AFP positivity and tumor size, tumor encapsulation, degree of vascular invasion, or the histological differentiation grade of the tumor. The patients with AFP-positive carcinomas had a poorer prognosis than did those with AFP-negative carcinomas (5-year survival rate of AFP-positive and negative groups were 26.7% and 56.5%, respectively.

A Position-Dependent Silencer Plays a Major Role in Repressing α-Fetoprotein Expression in Human Hepatoma

A large percentage of human hepatomas produce alpha-fetoprotein (AFP), but the levels of AFP expression vary greatly among hepatomas. To understand the molecular basis for this variation, we analyzed transcriptional regulatory activities associated with the 5'-flanking region of the AFP gene in two human hepatoma cell lines, HuH-7 and huH-1/cl-2, which produce a high and a low level of AFP, respectively. We found that the low level of AFP production in huH-1/cl-2 is due to the action of at least two silencer regions located between the enhancer and the promoter of the AFP gene. In contrast, no silencer activity is expressed in HuH-7. We identified 5'-CTTCATAACTAATACTT-3' to be a core sequence responsible for the negative regulatory activity. This sequence is repeated four times in a strong, distal silencer region, Sd, whereas one copy is present in a weak, proximal silencer region, Sp. The silencer reduces transcriptional initiation by blocking enhancer activation of the AFP promoter in a position-dependent manner. The silencer functions in the presence of positive transcription factors and may play a key role in developmental repression as well as variable expression of the AFP gene in hepatomas.

A position-dependent silencer plays a major role in repressing alpha-fetoprotein expression in human hepatoma.

A large percentage of human hepatomas produce alpha-fetoprotein (AFP), but the levels of AFP expression vary greatly among hepatomas. To understand the molecular basis for this variation, we analyzed transcriptional regulatory activities associated with the 5'-flanking region of the AFP gene in two human hepatoma cell lines, HuH-7 and huH-1/cl-2, which produce a high and a low level of AFP, respectively. We found that the low level of AFP production in huH-1/cl-2 is due to the action of at least two silencer regions located between the enhancer and the promoter of the AFP gene. In contrast, no silencer activity is expressed in HuH-7. We identified 5'-CTTCATAACTAATACTT-3' to be a core sequence responsible for the negative regulatory activity. This sequence is repeated four times in a strong, distal silencer region, Sd, whereas one copy is present in a weak, proximal silencer region, Sp. The silencer reduces transcriptional initiation by blocking enhancer activation of the AFP promoter in a position-dependent manner. The silencer functions in the presence of positive transcription factors and may play a key role in developmental repression as well as variable expression of the AFP gene in hepatomas.

Alpha‐fetoprotein in fetal serum, amniotic fluid, and maternal serum

In order to gain more insight into the association between alpha-fetoprotein (AFP) and fetal chromosomal disorders, especially Down's syndrome, we measured AFP in fetal serum, amniotic fluid, and maternal serum at cordocentesis. We compared the concentration and gradient of AFP in these three compartments. Our data confirm earlier findings on second-trimester fetal serum AFP concentration. The results indicate that low maternal serum AFP in pregnancies with fetal chromosomal disorders could result from an impaired fetal kidney function as well as from impaired membrane or placental passage of AFP, rather than from reduced fetal AFP production.

Interleukin‐1 and Tumor Necrosis Factor‐α Inhibit Erythropoietin Production in Vitroa

The effects of several immunomodulatory peptides (recombinant, human) on the in vitro production of erythropoietin (Epo) were studied in cultures of the human hepatoma cell line Hep G2. A dose-dependent decrease of up to 60% in Epo production was induced by interleukin-1 beta, interleukin-1 alpha, and tumor necrosis factor-alpha (in that order of potency). In contrast, moderately increased Epo levels resulted with interleukin-6 or interferon-gamma treatment at high concentrations. Concomitant measurements of the production of alpha-fetoprotein indicated that the observed effects were specific for Epo. Hence, we suspect a modulating role of the immune system in the in vivo control of Epo production and postulate that interleukin-1 and tumor necrosis factor-alpha are involved in some of the cases of lowered blood Epo levels in association with renal diseases, chronic inflammation, and malignancies.

Differentiating effect of sodium butyrate on human hepatoma cell lines PLC/PRF/5, HCC‐M and HCC‐T

The in vitro effect of sodium butyrate (SB) on human hepatoma cell lines PLC/PRF/5, HCC-M and HCC-T was investigated. SB was added at the non-toxic but cytostatic concentration of 1 mM. In all these cell lines, SB reduced cell proliferation and changed the morphology of the cells into a fibroblast-like shape. In PLC/PRF/5, alpha-fetoprotein production and c-myc expression were inhibited. In contrast, gene expression of albumin, one of the normal liver-cell products, and that of integrated hepatitis B virus genome, was increased. In HCC-M and HCC-T, c-myc expression, which was enhanced in the naive state, was reduced. In HCC-M, fos expression was inhibited but the expression of N- and K-ras genes did not change. SB seemed to induce normal or mature properties of hepatocytes in human hepatoma cell lines.

Alpha‐fetoprotein‐producing Papillary Adenocarcinoma Originating from a Uterine Body A Case Report

A rare case of alpha-fetoprotein (AFP)-producing papillary adenocarcinoma originating from the uterine body of a 55-year-old Japanese woman is reported. The histologic appearance of the tumor was reminiscent of a serous papillary carcinoma of the ovary, in clear contrast to that of common endometrial adenocarcinomas. No features of embryonal carcinoma or yolk sac tumor were evident. Immunohistochemical examination demonstrated the production of AFP by the tumor cells. To our knowledge there are six reported cases of AFP-producing malignant tumors of the uterine body in the literature, four of them being yolk sac tumor, one mixed mesodermal tumor, and one endometrial adenocarcinoma. This is therefore the first case of an AFP-producing papillary adenocarcinoma that developed in the uterine body. This report should contribute to a better understanding of the histogenesis of AFP-producing tumors in this organ.

Effects of cytokine combinations on acute phase protein production in two human hepatoma cell lines.

We evaluated the effects of binary combinations of four cytokines on production of the positive acute phase proteins alpha-1 antichymotrypsin, haptoglobin and fibrinogen, and the negative acute phase proteins albumin and alpha-fetoprotein (AFP) in two human hepatoma cell lines. The effects of the cytokine combinations on the five proteins varied; each protein exhibited a unique and specific pattern of response to the cytokine combinations. In Hep G2 cells, antichymotrypsin was induced by all four cytokines, IL-6, IL-1, TNF-alpha, and transforming growth factor beta 1 alone, and their effects in binary combinations could be attributed to additive or minimally synergistic interactions. Fibrinogen was induced only by IL-6 and this induction was inhibited by IL-1 alpha, TNF-alpha or transforming growth factor beta 1. Haptoglobin was also induced only by IL-6, but TNF-alpha was the only cytokine that inhibited this induction at all concentrations of IL-6. Each of the four cytokines alone down regulated production of AFP and albumin. However, binary combinations of the four cytokines were simply additive, for the most part, in inhibiting AFP production, whereas the inhibitory effects of combinations of cytokines on albumin production differed significantly from simple additive effects. These observations, taken together with studies of effects of cytokine combinations on other acute phase proteins, indicate that the various acute phase proteins respond differently to different combinations of cytokines and that the potential exists for highly specific regulation of synthesis of individual plasma proteins by cytokine interactions. These findings imply that the acute phase response in vivo represents the integrated sum of multiple, separately regulated changes in gene expression.

A CASE OF α-FETOPROTEIN (AFP) PRODUCING CANCER OF THE DUODENUM

A 65-year-old man with the chief complaint of tarry stool and abnormal shadow on chest roentogenogram was admitted to our hospital and was diagnosed as having a thoracic aortic aneurysm and duodenal cancer with liver metastasis. Alpha fetoprotein (AFP) level of 491.2 ng/ml was revealed on admission. First of all, we performed distal gastrectomy including the first portion of the duodenum in order to prevent massive bleeding. Tumor's type was Borrmann III and clinical stage was stage IV. Histological examinations revealed that the tumor was consistent with hepatoid adenocarcinoma. Production of AFP in the tumor was demonstarated by immunohistochemical technique (abidin-biotin peroxidase complex method). On the other hand, aneurymsmectomy and patch angioplasty were carried out for the thoracic aortic aneurysm. Finally, transarterial embolization was performed to the liver metastsis.AFP is a typical carcinoembryonic protein, but positive AFP values are very rarely reported in duodenal cancer. Here we describe a case of duodenal cancer, which showed a markedly elevated serum AFP and existence of AFP positive tumor cells evidenced by a use of immunohistochemical staining.

Acyclic retinoids and cancer chemoprevention

Abstract

FOUR CASES OF ALPHA-FETOPROTEIN PRODUCING GASTRIC CANCER

We experienced four clinical cases of alpha-fetoprotein (AFP) producing gastric carcinoma. Those four cases were difinitely diagnosed as AFP producing gastric carcinoma, because the serum levels of AFP decreased significantly after surgical removal of the tumors and the localizations of AFP in tumor tissues were demonstrated in all resected specimens by immunohistochemical study (peroxidase-anti-peroxidase; PAP method). It is said that AFP producing gastric carcinomas are characterized by advanced gastric cancer and histologically undifferentiated or poorly differentiated adenocarcinoma.These four cases also had advanced gastric carcinoma, which were histopathologically papillary, medullary, poorly differentiated and well differentiated adenocarcinomas respectively. AFP producing gastric carcinomas are frequently accompanied with liver metastasis and the prognosis is miserable. Of these 4 cases, 2 already had liver metastasis at surgery, and one developed liver metastasis in an early period after surgery. Their prognoses were poor such as one year survival rate of 25% and the 2 year rate of 0%. From the above, the importance of some strategies or efforts for preventing liver metastasis is emphasized even after curative resection could be attained.

Unique structure of glycopeptide from alpha-fetoprotein produced in human hepatoma cell line, as determined by 1H-nuclear magnetic resonance spectroscopy

Determination of alpha-fetoprotein is used in diagnosis of tumors and neural tube defects. A good reliable source of alpha-fetoprotein would be an obvious advantage to the preparation of diagnostic reagents and their standardization. We have recently developed a method for the production of alpha-fetoprotein from a human hepatoma cell line. This method, which is suitable for scaling up, allowed us to produce 40 g of alpha-fetoprotein from culture supernatant liquid through a simple purification procedure. We have previously shown this protein to be identical to alpha-fetoprotein produced from other sources. However, because the presence of different glycoforms has been reported in alpha-fetoprotein preparations, both from human sources and from other species, it was important to establish the type and extent of glycosylation of alpha-fetoprotein prepared by our method. By using 1H-NMR spectroscopy we were able to establish that our product contains a single N-linked biantennary, fully sialylated complex-type oligosaccharide, typical of human hepatomas.

Alpha-fetoprotein (AFP)-producing gastric carcinoma. Is it hepatoid differentiation?

Biochemical and immunohistochemical analyses were done on five cases of gastric carcinoma with excessive production of alpha-fetoprotein (AFP). Histologic and ultrastructural examination of these cases showed conventional poorly differentiated adenocarcinoma of cuboidal or polygonal tumor cells in the medullary area with scattered AFP-positive cancer cells. Comparative studies on serum AFP between these cases and in hepatocellular carcinoma (HCC) or in testicular yolk sac tumor cases using concanavalin A (ConA)-affinity and lens culinalis agglutinin A (LCA)-affinity sepharose columns revealed that the AFP derived from four cases had a high ConA nonadsorping rate and high LCA-reactive fraction similar to that of yolk sac tumor. The AFP from one case had a small LCA-reactive fraction similar to that of HCC. Further immunohistochemical study using several markers for liver cells or germ cell tumor did not show additional evidence of these tumor cells to differentiate into liver cells or yolk sac tumor cells. Thus, this study indicates that AFP-producing gastric carcinomas are not always derived from hepatoid differentiation of the foregut. These gastric carcinomas might be categorized into medullary tumor with gastrointestinal tract-specific AFP.

Effects of laminin and collagen type I on the morphology and secretion of proteins in human hepatoblastoma and hepatoma cell lines.

The effects of laminin (LAM) and collagen type I (C-I) on human hepatoblastoma (HuH-6) and hepatoma (HuH-7) cell lines were investigated. C-I was superior to LAM in supporting the attachment of the cells, especially of HuH-6, to plastic surfaces. No effect of LAM and C-I on cellular morphology was recognizable by phase contrast microscopy. By scanning electron microscopy (SEM), much more microvilli were found on the cell surface of HuH-6 on LAM substrate than on C-I substrate. In HuH-7 cells, however, these microvilli were rarely found on either LAM substrate or C-I substrate. The gel profile of the proteins secreted by HuH-6 and HuH-7 cells was not affected by the culture substrate except for the major band, though the amount of alpha-fetoprotein (AFP) secreted was larger when the cells were cultured on LAM substrate than on C-I substrate. These results indicate that the ability of LAM or C-I to enhance attachment is different from that to enhance AFP production or microvilli expression in HuH-6 cells and probably in HuH-7 cells.