Characteristics of antigens from an HCG alpha secreting cell line (ElCo) derived from human breast carcinoma in a Native American patient.

Objective: Our purpose is to report a cell line derived from a Native American patients that could serve as a model for ethnic diversity in cell culture research.

Study Design: Tumor biopsy specimens from reproductive tract malignancies were explanted in the cell culture laboratory. Characterization of a successfully established line included a parameter commonly observed in minority populations in rapid moving Type A glucose-6-phosphate dehydrogenase enzyme (G6-PD).

Gestational trophoblastic disease and human chorionic gonadotropin measurement.

Improved radioimmunometric assays for the glycoprotein human chorionic gonadotropin, its whole molecule and free beta and alpha subunits have improved the capability for trophoblast tumor detection and monitoring. New heights in survival rates have been reached with these improvements, particularly in high-risk disease.

Characterization of human chorionic gonadotropin in urine of patients with trophoblastic diseases by Western blotting using specific antibodies.

Human chorionic gonadotropin (hCG) from urine of patients with trophoblastic diseases was analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), followed by Western blotting using specific antibodies. Western blotting using anti-hCG beta carboxy-terminal peptide (CTP) revealed that the molecular weights of the beta subunits of the three molar hCG samples were identical to that of standard hCG beta, but those of choriocarcinoma hCG samples were individually different. In the five choriocarcinoma hCG samples, the beta subunits of three samples were apparently larger than standard hCG beta, while those of two samples were smaller than standard hCG beta but larger than desialylated standard hCG beta.

Discordant induction of tumor-associated antigen, TA-4 and chorionic gonadotropin beta in cultured cervical carcinoma cells.

The CaSki cell line derived from an epidermoid carcinoma of the uterine cervix produces and releases two types of tumor-associated antigen. One is a eutopic antigen, TA-4 and the other is an ectopic antigen, hCG beta-like material. The aim of the present investigation was to elucidate a possible difference in the induction mechanism of production of TA-4 and hCG beta-like material in the CaSki cells in relation to cellular differentiation and gene modulation.

Production of tumor-associated antigen, TA-4, by the CaSki cervical carcinoma cell line.

Previous Japanese studies described the purification of TA-4 from homogenates of tumor tissues excised from squamous cell carcinomas of the uterine cervix, and the development of a radioimmunoassay to detect TA-4 in sera of patients with this disease. The aim of the present investigation was to determine if TA-4 was produced by the CaSki cell line, established in culture ten years ago from epidermoid carcinoma of the uterine cervix. The radioimmunoassay detected the TA-4 antigen in the CaSki cells, but not in cell lines derived from either choriocarcinoma or breast carcinoma.

A distinctive form of human chorionic gonadotropin beta-subunit-like material produced by cervical carcinoma cells.

The DoT and CaSki human cervical carcinoma cell lines ectopically produce material immunologically similar to the beta-subunit of human chorionic gonadotropin (hCG beta). Culture fluids were analyzed by gel filtration chromatography and radioimmunoassay (RIA) using (a) antiserum directed to conformation-specific (core-directed) determinants not involving the carboxyl-terminal peptide (CTP) in hCG beta purified from urinary hCG (i.e.

Optimization of the production of hCG beta-like material by CaSki human cervical carcinoma cells in roller bottle culture.

This study was aimed at optimizing large-scale roller bottle culture conditions for CaSki human cervical carcinoma cells, to produce ectopic hCG beta-like material in quantities sufficient for subsequent characterization studies. Several cell culture techniques contributed to the achievement of this goal: (1) use of serum-free culture medium; (2) use of intermittent recovery periods in presence of serum; and (3) ultrafiltration of the serum-free medium pool for initial concentration of 100-fold.

Linkage of human chorionic gonadotrophin and placental lactogen biosynthesis to trophoblast differentiation and tumorigenesis.

Normal trophoblast of the human placenta elaborates at least two major protein hormones, chorionic gonadotrophin (hCG) and placental lactogen (hPL). Molar and choriocarcinoma tissues characteristically synthesize large amounts of hCG and hPL. To examine the role of trophoblast differentiation in the expression of the hCG and hPL genes, we studied the cytological distribution of their mRNAs in tissue sections of human hydatidiform mole and choriocarcinoma by in situ hybridization.

Estrogen synthetase stimulation by hemin in human choriocarcinoma cell culture.

The ability of hemin to stimulate estrogen synthetase (aromatase) in cultured human trophoblast cells and in cellular homogenates was investigated and compared with aromatase stimulation by dibutyryl cAMP [(Bu)2 cAMP]. Cells grown with hemin for 24 h, or homogenates incubated for 45 min with hemin, showed maximal aromatase stimulation (150 to 200% of activities in the absence of hemin) at 25 microM and 0.1 microM, respectively.

Discordant human chorionic gonadotropin results: causes and solutions.

This study was performed to demonstrate the phenomenon of discordant human chorionic gonadotropin (hCG) results, in which some serum specimens are positive in one hCG detection procedure but negative in another procedure. Nine different quantitative hCG procedures were used to document discordant hCG results in 22 cases. A two-site monoclonal antibody immunoradiometric assay had the least tendency to give aberrant low-positive hCG values in nonpregnant patients without neoplasms.

Phototoxic effects of hematoporphyrin derivative and its chromatographic fractions on hormone-producing human malignant trophoblast cells in vitro.

The in vitro phototoxicity of HPD on malignant cells relative to normal cells has been examined. Two human malignant cell lines were studied: the BeWo line of choriocarcinoma cells, which secrete the tumor marker human chorionic gonadotropin (hCG) and its alpha-subunit; and the CaSki line of human cervical carcinoma cells, which secrete hCG and its beta-subunit. Trophoblast-derived, hCG-secreting cells from human amniotic fluid were used as normal controls.

The hCG assay in the treatment of trophoblastic disease.

The most important criterion in monitoring the treatment of patients with trophoblastic disease is the quantitative measurement of hCG levels. It is particularly important to have a sensitive hCG-detection procedure that reliably distinguishes low positive hCG levels from negative ones. Reliable monitoring of serum hCG levels minimizes unnecessary chemotherapy in patients entering remission and provides an early indication for additional chemotherapy if and when the hCG levels again become detectable.

Differential occurrence of free beta and free alpha subunits of human chorionic gonadotropin (hCG) in pregnancy sera.

Levels of hCG alpha beta dimer, free alpha-subunit and free beta-subunit were measured in pregnancy sera. Dimer and free alpha were quantitated by radioimmunoassays (RIAs) using specific polyclonal antisera. Free beta was quantitated both by monoclonal anti-beta RIA and by polyclonal anti-beta RIA following the complete adsorption of cross-reacting hCG by immobilized alpha-antisera.

Choriocarcinoma: blocking factor and monoclonal antibody iodine 131 imaging.

Postoperative iodine 131 monoclonal antibody localization in metastatic choriocarcinoma was accomplished in this study. The monoclonal antibody was prepared to male choriocarcinoma which cross reacted with gestational choriocarcinoma. The antibody was raised against whole choriocarcinoma cells and human chorionic gonadotropin (hCG) cross reactivity was excluded.

Segregation patterns of polymorphic restriction sites of the gene encoding the alpha subunit of human chorionic gonadotropin in trophoblastic disease.

The gene encoding the alpha subunit of human chorionic gonadotropin contains at least two polymorphic sites in its 3' flanking region detected by restriction enzymes HindIII and EcoRI. We used these polymorphic sites as markers of tissue genotype in normal placenta, hydatidiform mole, choriocarcinoma, and peripheral leukocytes. As expected, inheritance patterns of most hydatidiform moles showed only a paternal genetic contribution.

Alpha subunit and human chorionic gonadotropin in normal pregnancy and gestational trophoblastic disease.

The reported incidence of gestational trophoblastic disease is an order of magnitude higher in Nigeria than in the United States. Sera from a total of 283 pregnant black patients, 138 United States and 148 Nigerian pregnant patients, were analyzed for their serum levels of alpha subunit and human chorionic gonadotropin (hCG). The patterns of hCG secretion were similar in the two populations during normal pregnancy.

The role of trophoblast differentiation in the control of the hCG and hPL genes.

Normal trophoblast of the human placenta elaborates at least two major protein hormones, hCG and hPL. Molar and choriocarcinoma tissues characteristically synthesize large amounts of hCG and small quantities of hPL. To examine the role of trophoblast differentiation in the expression of the hCG and hPL genes, we studied the cytological distribution of their mRNAs in tissue sections of human hydatidiform mole and choriocarcinoma by in situ hybridization.

The carbohydrate on human chorionic gonadotropin produced by cancer cells.

Using the methods described, it is not possible to determine the number of N- and O-linked oligosaccharides on ectopic hCG beta. On standard hCG beta there are two NeuAc residues on each N- and O-linked oligosaccharide, so that the number of NeuAc residues is proportional to the number of oligosaccharides. Ectopic hCG beta and desialylated ectopic hCG beta are of similar molecular size to the standard preparations (gel filtration and RIA with anti-CTP antisera, data not presented).

New horizons in hCG detection.

The advent of high technology in the field of hCG measurement has created a greater requirement for high expertise in the analysis and evaluation of hCG levels, particularly low-positive levels, and for the concomitant clinical management of the patient. This implies an imperative to treat trophoblastic disease patients in trophoblast disease referral centers.

Cytological distribution of chorionic gonadotropin subunit and placental lactogen messenger RNA in neoplasms derived from human placenta.

Normal trophoblast of the human placenta elaborates at least two major protein hormones, chorionic gonadotropin (hCG), and placental lactogen (hPL). There are several gestational trophoblastic diseases of the placenta called hydatidiform mole, invasive mole, and choriocarcinoma. Molar and choriocarcinoma tissues characteristically synthesize large amounts of hCG and small quantities of hPL.