Quantitative estimation of an alpha 2 pregnancy-associated protein in normal pregnancy by electroimmunoassay

Long-term culture of HepG2 hepatoma cells as a model for liver acute phase response during chronic inflammation. Effects of interleukin-6, dexamethasone and retinoic acid

HepG2 cells were cultured for 7 days in serum-free medium in the presence of interleukin-6 (IL-6), retinoic acid (RA) or dexamethasone (DX), and some plasma proteins secreted to the media were determined by electroimmunoassay whereas the contents of specific mRNAs in the cells was evaluated by Northern blot hybridization. Interleukin-6 maximally stimulated synthesis of alpha-1-antichymotrypsin between days 1 and 3 whereas the response of fibrinogen was delayed to days 3 to 7. Retinoic acid increased the effect of IL-6 on alpha-1-antichymotrypsin (ACT) and fibrinogen (FBG) on the level of both proteins and mRNAs. Synthesis of albumin was slightly inhibited by IL-6 and RA, and synthesis of transferrin was increased by RA but not by IL-6. Dexamethasone had small enhancing effect on the action of IL-6. These results suggest that long-term HepG2 cultures may provide an experimental model for liver acute phase response during chronic inflammation.

A novel tumor-associated protein: clinical significance of serum levels in various clinical conditions with special reference to gynecological malignant diseases

A novel tumor-associated protein (TAP), that was originally detected immunologically through the use of a monospecific antiserum against a placental antigen, was quantified by means of the rocket technique of Laurell. Four hundred and fifty-seven serum samples were obtained from healthy female subjects (55), and patients with leiomyomas (162), benign ovarian tumors (78), pelvic endometriosis (45), cervical cancer (73), endometrial cancer (18) and ovarian cancer (26), respectively. Statistical analysis showed that TAP exhibited the closest relationship in ovarian cancer patients in whom the appearance of TAP and its high level were most prominent. The present preliminary study suggests the clinical usefulness of this protein as a clinical adjunct for the management of ovarian cancer.

Identification of an ectopic developmental antigen that appears in malignant ascitic fluid

A tumor-associated antigen that shares antigenicity with a pregnancy-associated protein has been detected in ascitic fluid of patients with advanced ovarian cancer. The protein, prepared from malignant ascitic fluid by the combination of poly(ethylene glycol) 4000 fractionation, DEAE-Sepharose column chromatography and preparative polyacrylamide gel electrophoresis (PAGE), was subsequently separated on sodium dodecyl sulfate-PAGE, as a single band corresponding to an approximate molecular mass of 91 kDa. Immunological analysis showed that this protein was a circulating species of an ectopic developmental antigen that markedly increases in biological fluids in tumor-bearing statuses.