A New Carcinoembryonic Protein Characterized by Basic Property

Identification of human basic fetoprotein as glucose-6-phosphate isomerase by using N- and C-terminal sequence tags and terminal tag database

Human basic fetoprotein (BFP), found in fetal serum and tissue extracts as well as in extracts of various cancer tissues, has long been known as a marker protein for cancers; however, the primary sequence has not yet been reported. This paper describes the identification of BFP using the N- and C-terminal amino acid sequence tags (Ac-AALTRDPQFQ and QQREARVQ, respectively) clarified by mass spectrometry-based methods, and a terminal tag database (ProteinCarta). In this study, BFP was identified as glucose-6-phosphate isomerase (G6PI_HUMAN).

A clinical study of urine basic fetoprotein and urine polyamine as tumor markers in epithelial cancer of the urinary tract

BACKGROUND

The reliability of a new screening test for epithelial cancer of the urinary tract was evaluated and the results were compared with those obtained employing urinary cytology in routine use.

METHODS

The subjects consisted of 187 cases selected randomly from among the patients who attended Toho University Ohashi Hospital during a period of 1 year from January 1998. The values for urine basic fetoprotein (BFP) and polyamine and urinary cytology were examined.

RESULTS

Urine BFP is considered useful for screening and monitoring urinary tract epithelial cancer as is urinary cytology. Urine BFP showed a statistically significant difference (P < 0.05) for G1 compared with urinary cytology and a significantly high level compared with urinary cytology as to the positive rate in the low stage group (P < 0.05). The positive rate of urine BFP was high in patients with urinary tract infection.

CONCLUSION

Determining urine BFP, when combined with urinary cytology, is considered very useful for diagnosing patients with urinary tract epithelial cancer. This study suggests the possibility of urine BFP being superior to urinary cytology for screening early cancer and also as an indicator for observations on the clinical course.

Basic fetoprotein in normal and pathologic urine

We developed a latex agglutination nephelometric immunoassay for urinary basic fetoprotein (BFP) that functioned well and had good specificity, precision, and recovery. Reference intervals started below 0.5 microgram/L, the lower limit of the range of sensitivity of the assay, and went up to 7.0 micrograms/L at the 97.5th percentile without age- or sex-related variation, in accordance with the NCCLS guidelines. BFP was unstable at pH 5.0 at 4 degrees C and 25 degrees C. The western blot method showed BFP found in the semen to be structurally identical to purified BFP from hepatoma ascites, in which concentration ranged from 94.2 to 145.2 micrograms/L and, further, to have the same molecular weight and reactivity with a monoclonal antibody. BFP levels were elevated in cases urinary BFP concentration included ureter stone, infection, and prostate and bladder cancer. Moreover, BFP concentration correlated closely with that of alpha 2-macroglobulin, indicating that BFP is probably secreted locally in close pathophysiologic association with post-renal hemorrhage. We thus conclude that BFP is a urinary nonspecific marker for inflammation or tumor. The best indication for BFP as a tumor marker may be follow-up when diagnosis of genitourinary cancer is definite.

Urinary basic fetoprotein in the diagnosis and follow-up of patients with urothelial carcinoma

BACKGROUND

Urothelial carcinoma is one of the most common malignant neoplasms of the urinary tract and is characterized by a high local recurrence rate. However, no specific and reliable tumor marker has been identified for the diagnosis and follow-up of patients with urothelial carcinoma.

METHODS

Urinary basic fetoprotein (U-BFP) levels were measured by enzyme immunoassay in 119 patients with urothelial carcinoma, 64 patients with other urologic malignancies, 144 patients with benign diseases, and 166 healthy individuals to evaluate it clinical efficacy as a marker of urothelial carcinoma. The histologic logic localization of BFP was also studied. A cutoff value was set at 14 ng/mL based on the maximum diagnostic efficiency.

RESULTS

The specificity and sensitivity of U-BEP for urothelial carcinoma was 91.7% and 58%, respectively. THe U-BFP positive rate increased significantly with the histologic grade. The U-BFP positive rate was higher in both Tis and T2-4 than in Ta, 1 disease. The U-BFP level exceeded the cutoff value before curative therapy in 32 patients; U-BFP was normalized in 97% of these patients within 2 weeks after therapy. There was a total of 11 recurrences and the U-BFP level returned to abnormally high levels in all instances. Histologic localization of U-BFP was demonstrated in the cytoplasm of the tumor cells in 80% of the patients.

CONCLUSION

Based on these results, U-BFP is a potential tumor maker of urothelial carcinoma. In particular, the test could be used to monitor patients whose U-BFP value is positive before therapy.

Production of basic fetoprotein in human peripheral lymphocytes during blastic transformation

To clarify the significance of basic fetoprotein (BFP) in lymphocytes, we investigated whether BFP is produced in lymphocytes during blastic transformation. Peripheral blood lymphocytes obtained from 14 adults were cultured under the stimulation of lectins. The concentration of BFP in the culture medium (extracellular BFP) was estimated serially. The incorporation of [6-3H]-thymidine was assayed simultaneously. The intracellular BFP was measured by dual flow cytometry for DNA and BFP. A lymph node was studied immunohistochemically. Serum BFP was measured in four cases of lymphocytic leukaemia. In two cases, dual staining was performed. The intracellular BFP of the mitogen-stimulated lymphocytes was increased within 24 h. The extracellular BFP was increased exponentially from 72 h. The extracellular BFP at 96 h did not correlate with the [3H]-thymidine incorporation. The intracellular BFP increase began in G1 phase. Immunostaining showed that the B cells also produced BFP. The serum BFP level in leukaemia was high in 1 of 4 cases and the leukaemic cells in two cases showed high intracellular BFP content. These observations indicate that BFP is produced in activated human lymphocytes and in lymphocytic leukaemic cells. The production of BFP during blastic transformation will be a useful new in vitro model for studying the biological role of BFP, and BFP labelling may offer some new possibilities for the study of lymphocytes.

Preliminary Study on Auxiliary Value of Serum Basic Fetoprotein in Diagnosing Lung Cancer

To characterize basic fetoprotein (BFP) as a new tumor marker, we measured serum levels of BFP and 5 other tumor markers (CA19-9, CEA, NSE, SCC, and TPA) concomitantly in 65 patients with lung cancer, 57 patients with benign pulmonary disease, and 40 healthy volunteers. The sensitivity of BFP was 43%, the specificity 82% and the accuracy 61%. The positivity increased in relation to stage of the disease. There was no correlation between positivity of BFP and histologic type. On the whole, BFP appeared to be analogous to TPA in terms of broad spectrum and to have an auxiliary value in diagnosing lung cancer.

Serum basic fetoprotein in patients with renal cell carcinoma

Serum basic fetoprotein (BFP), immunosuppressive acid protein (IAP), and tissue polypeptide antigen (TPA) levels were measured in patients with renal cell carcinoma. The positive rates of serum BFP, IAP, and TPA were 47%, 79%, and 42%, respectively. Serum levels and positive rates were found to be elevated according to the degree of disease advancement. Using a combined assay for the three markers, the positive rate for BFP, IAP, and TPA was 92%, and approximately 100% in Stages II, III, and IV of the disease. Therefore, the combined marker assay improved the diagnosis of renal cell carcinoma. In curative resection patients, the percent of patients whose serum BFP levels returned to normal 1 week after the operation was 85. This was higher than the IAP or TPA levels (18% and 67%, respectively). Moreover, in inoperable patients, serum BFP levels showed a better correlation with the clinical course than serum IAP or TPA levels. Serum BFP is useful for monitoring patients with renal cell carcinoma who have an elevated BFP value.

Clinical evaluation of basic fetoprotein in testicular cancer

We attempted to determine the efficacy of basic fetoprotein as a marker in testicular cancer. The levels of serum basic fetoprotein were studied in 58 patients (31 with seminoma and 27 with nonseminoma). Elevated levels were observed in 22 seminoma (71 per cent) and 15 nonseminoma (56 per cent) patients, while the levels of other markers (beta-subunit of human chorionic gonadotropin, alpha-fetoprotein and lactic dehydrogenase) remained normal in 6 seminoma (19 per cent) and 2 nonseminoma (7 per cent) patients. The levels of basic fetoprotein changed in relation to the clinical courses and they elevated again in 3 of 4 patients with recurrence. The concentration of basic fetoprotein in testicular cancer tissue was significantly higher than in the normal testis. Histological localization of basic fetoprotein in testicular cancer tissue was demonstrated immunohistochemically. Thus, basic fetoprotein was considered to be a useful serum marker for testicular cancer.

Serum tumor markers in patients with hepatocellular carcinoma: diagnosis of alpha-fetoprotein -low or -negative patients

The presence of specific gamma-glutamyl transpeptidase isoenzyme (gamma-GTPI) and variant alkaline phosphatase (VAALP) were concurrently determined, and levels of basic fetoprotein (BFP) and carcinoembryonic antigen (CEA) in addition to alpha-fetoprotein (AFP) were measured in 144 hepatocellular carcinoma (HCC) patients in order to evaluate the diagnostic value of these tumor markers with respect to AFP-low or -negative patients and the tumor stage. Serum AFP levels below 400 ng/ml, commonly seen in sera of hepatobiliary diseases other than HCC, were noted in 42% of the patients. The diagnostic usefulness was increased by combination assay of these markers except for CEA. A definitive diagnosis of HCC could be made in 78% of the patients by a combination of gamma-GTPI, VAALP and AFP. Moreover, a diagnosis of malignancy could be made in 87% of cases by the inclusion of BFP. The prevalence of BFP and CEA increased in proportion to the tumor stage, whereas that of AFP and gamma-GTPI were independent of stage and were high even in patients in comparatively early stages. Furthermore, secreting type markers such as AFP and gamma-GTPI were relatively useful for diagnosis of HCC when the lesions were still small.

A suprasellar embryonal carcinoma producing alpha-fetoprotein and human chorionic gonadotropin; treated with combined chemotherapy followed by radiotherapy

A case of primary suprasellar embryonal carcinoma that produced alpha-fetoprotein and human chorionic gonadotropin in a 12-year-old girl is reported. Partial removal of the tumor and cis-platinum-based combined chemotherapy followed by local radiotherapy resulted in a definite regression of the tumor and improvement from clinical signs and symptoms. After these treatments, the concentrations of alpha-fetoprotein and human chorionic gonadotropin in both serum and cerebrospinal fluid decreased to undetectable levels. Serum basic fetoprotein, another tumor marker, can be a tool for evaluating the clinical course following postoperative chemotherapy.