Recombinant human leukocyte interferon-alpha 2b stimulates the synthesis and release of a 90K tumor-associated antigen in human breast cancer cells

We have previously reported the production of a new monoclonal antibody (MAb) (SP-2) recognizing a 90-kDa tumor-associated antigen, termed 90K, which is increased in the serum of many cancer patients. Treatment of CG5 human breast cancer cells with recombinant interferon-alpha 2b (rIFN-alpha 2b) can increase the synthesis and release, in culture medium, of the 90K. The effect of rIFN-alpha 2b was dose-related and occurred at concentrations which did not affect cell proliferation. The increase of 90K expression was due to de novo protein synthesis since cycloheximide, added within 3 hr of the beginning of rIFN-alpha 2b stimulation treatment, completely abolished the effect of rIFN-alpha 2b. The stimulatory effect of rIFN-alpha 2b was already evident after 24 hr treatment. Finally, an increase in serum 90K levels was observed in 3 patients with advanced breast cancer receiving a short course of rIFN-alpha 2b (Intron A). No effect of rIFN-alpha 2b was seen in 3 normal women. The ability of rIFN-alpha 2b to increase the synthesis and release of 90K both in vitro and in vivo may be of clinical importance in the early detection of tumors.

Measurement of a monoclonal-antibody-defined antigen (90K) in the sera of patients with ovarian cancer

Serum levels of CA125 and 90K, a new tumor-associated antigen, were measured in 73 ovarian cancer patients and 70 patients with benign gynecological conditions. Abnormally high serum CA 125 and 90K levels were found in 49% and 78% of these patients, respectively. When a combination of the two markers was used, the sensitivity increased to 86%. The percentage of 90K positivity did not significantly correlate with stage of disease or with histological type. A statistically significant correlation was found between 90K positivity rate and grade of tumor differentiation. Elevated serum CA 125 and 90K levels were present in 32% and 29% of patients with benign ovarian tumors, respectively. Only 1 case out of 26 with endometriosis had high 90K levels, compared to 7 patients with abnormal CA 125 levels. Serial measurements of 90K concentrations were found to be correlated with the clinical behaviour of the disease during chemotherapy. Moreover, rising levels of 90K preceded the clinical detection of recurrence with a median lead-time of 3 months. In 2 of these cases the serial changes in 90K values were better correlated with the course of disease than changes in CA 125 levels. Our data suggest that 90K combined with CA 125 may be applied for the detection and monitoring of ovarian cancer.

Effects of antiestrogen and progestin on immune functions in breast cancer patients

Several immunologic variables were evaluated in 14 patients with untreated primary breast cancer and 20 postmastectomized patients undergoing tamoxifen (TAM) or high-dose medroxyprogesterone acetate (MPA) treatment. Immunologic evaluation in the peripheral blood included lymphocyte count, definition of T-lymphocyte subsets by monoclonal antibodies (OKT3, OKT11, OKT4, and OKT8), and lymphocyte blastogenic response to phytohemagglutinin (PHA) and Concanavalin A (Con A). Moreover, the in vitro effect of TAM and MPA on the blastogenic response of peripheral lymphocytes from normal female subjects was tested. Primary breast cancer patients did not differ from controls in any of the variables tested. Similarly, the immunologic variables of the group treated with TAM were normal, with the exception of a slight reduction of the OKT4+/OKT8+ ratio. In MPA-treated patients, a reduction of the percentage of OKT4+ cells and a decrease of the OKT4+/OKT8+ ratio were observed. Moreover, response to PHA was reduced sharply. However, the addition of interleukin-2 (IL-2) to the culture medium restored PHA response. Likewise, the in vitro addition of MPA to peripheral blood lymphocytes from normal female subjects resulted in a sharp dose-dependent depression of PHA response while TAM was ineffective completely. The inhibitory effect of MPA was not evident when IL-2 was added simultaneously to the culture medium. These results show that the administration of high-dose MPA may alter immunocompetence as defined by T-lymphocyte subsets and response to mitogens. The latter effect may be related to a diminished production of IL-2. In contrast, TAM does not appear to have a significant immunodepressant action either in vitro or in vivo.

CA 15-3 as a tumor marker in gynecological malignancies

Serum levels of CA 15-3 were measured in 778 samples from 270 patients with benign and malignant gynecological conditions. Malignant tumors were present in 180 patients including 58 cases with cancer of the ovary, 47 of the endometrium, 61 of the cervix, and 14 of the vulva. The 90 cases with benign conditions included 24 patients with ovarian tumors, 28 with fibromyomatosis, 18 with endometriosis, and 20 with endometrial hyperplasia. Of 180 cancer patients, CA 15-3 serum levels were elevated (greater than 30 U/ml) in 74 cases (41%) and the frequency of abnormal marker values increased with clinical stage. Of 90 patients with benign conditions, high CA 15-3 levels were found in 5 cases (6%) with benign ovarian tumors. Elevated levels of the marker were most commonly seen in ovarian cancer patients (71%). In endometrial, cervical, and vulvar cancer abnormal CA 15-3 values occurred in 32, 26, and 14%, respectively. In endometrial cancer the percentage of positive marker levels increased with more infiltrating and/or less differentiated tumors. A positive correlation was found between residual tumor after surgery and CA 15-3 levels. Serial measurements in sera of patients who underwent chemotherapy showed a good correlation with response to treatment. CA 15-3 values were correlated with clinical course of disease in 87% of cases.

Antiproliferative effects of somatostatin and the somatostatin analog SMS 201-995 on three human breast cancer cell lines

The antiproliferative effect of somatostatin and the somatostatin analog SMS 201-995 on three human breast cancer cell lines (CG5, T 47 D, and ZR 75-1) is reported. Both peptides markedly inhibited CG5 cell growth with a maximal inhibition of about 40% as compared with control cells. The antiproliferative effect of somatostatin on T 47 D and ZR 75-1 cells was much less evident. These results suggest that somatostatin is a peptide inhibitory factor for human breast cancer cells. Possible therapeutic implications of these findings are still to be investigated.

Measurement of a breast cancer associated antigen detected by monoclonal antibody SP-2 in sera of cancer patients

An enzyme-linked immuno-absorbent assay has been developed for the detection of a circulating tumor-associated antigen, 90K, recognized by murine monoclonal antibody SP-2 (Iacobelli et al., Cancer Res 46: 3005-3010, 1986). This assay was found to be simple and reproducible. Using this method, 6% of 165 apparently healthy individuals and 15% of 91 patients with benign breast disease showed 90K levels above 1.7 units/ml. Approximately 50% of 129 patients with advanced breast cancer demonstrated serum antigen levels above 1.7 units/ml. All histological types of breast cancer were positive, and no association between the incidence of elevated 90K levels and other prognostic variables could be detected. The titers of 90K were significantly higher in sera from advanced-stage (3 and 4) patients than in those from patients with limited-stage (1 and 2) disease. Elevated 90K levels were also observed in patients with carcinomas of other sites, including gastrointestinal, gynecological, and lung tumors. By means of the immune blotting technique, the antigenic components carrying the determinants in serum and extracts of breast cancer cells have been identified. The levels of 90K did not correlate with those of CA 15-3 or CEA. The measurement of 90K in sera appears to be a useful adjunct to other available assays for the detection and monitoring of breast cancer and other malignant tumors.

Neoadjuvant chemotherapy and radical surgery in locally advanced cervical carcinoma: a pilot study

Neoadjuvant chemotherapy with cisplatin, bleomycin, and methotrexate was used in the primary treatment of 33 consecutive patients with locally advanced cervical carcinoma (International Federation of Gynecology and Obstetrics [FIGO] stages IB-III; tumor volume greater than 4 cm). This therapy induced responses in 25 of the 33 patients (four complete, 21 partial; overall 75.7%), thus permitting radical surgery in all these cases despite initial bulky tumor. Surgery consisted of type III-IV radical hysterectomy plus systematic para-aortic and pelvic lymphadenectomy. The average number of lymph nodes removed was 63 (range 37-117). At histologic examination, complete responses were found in four cases (12.1%) and partial responses in 14 cases (42.4%). The highest response rates were found for vaginal disease (80%), followed by cervical disease (72%) and parametrial disease (63.1%). A lower than expected incidence of lymph node metastases was detected (16%, four of 25). Chemotherapy did not seem to complicate surgery in these circumstances. The combination of cisplatin, bleomycin, and methotrexate chemotherapy and surgery did not produce severe morbidity. However, chemotherapy-induced nausea and vomiting and moderate postoperative complications did occur. These encouraging preliminary results need a longer follow-up to evaluate the influence of treatment on disease-free survival.

Immunohistochemical localization of creatine kinase BB in primary breast cancer: correlation with estrogen receptor content

The brain-type (BB) isoenzyme of creatine kinase (CK) has recently been shown to be estrogen-regulated in human breast cancer cells in vitro. In this study we have correlated the presence of CK-BB, evaluated by immunoperoxidase procedures, with the estrogen receptor (ER) content in 35 primary breast cancers. Of 35 tumors examined, 66% revealed moderate to strong CK-BB immunoreactivity. Staining was exclusively located in the cytoplasm of neoplastic cells. A positive relationship was observed between CK-BB positivity and ER content with ER-rich tumors (greater than 50 fmoles/mg protein) showing a more intense immunoreactivity than ER-poor ones. The results indicate that CK-BB is estrogen-regulated in human breast cancer and suggest that evaluation of this enzyme may be of potential value for the detection of hormone responsive tumors.

Growth inhibitory effect of LH-RH analogs on human breast cancer cells

The antiproliferative effect of two LH-RH agonists (Pro 9-LH-RH ethylamide and D Ser(t BU)6 Aza Gly 10-LH-RH, ICI 118630) on the human breast cancer cell line CG5 is reported. Although ineffective when used alone, both analogs inhibited in a dose-dependent fashion the growth stimulatory effect of estradiol. LH-RH analogs did not influence the growth inhibitory effect of tamoxifen and medroxyprogesterone acetate. Likewise, these compounds neither modified basal estrogen and progesterone receptor levels nor prevented estrogen-induced increase of progesterone receptor. A marked antiproliferative effect of the analogs was also seen in cells stimulated with other mitogens, such as insulin and epidermal growth factor.

CA 15-3 serum levels in ovarian cancer

Serum levels of CA 15-3, an antigen expressed by human breast carcinoma cells, were measured in 58 ovarian cancer patients, 24 patients with benign ovarian tumor and 62 patients with benign gynecological conditions. Abnormally high serum CA 15-3 levels were found in 41 of 58 patients (71%) with ovarian cancer. The percentage of CA 15-3 positivity correlated with tumor stage. Elevated serum CA 15-3 levels were found in 5 of 24 patients (20%) with benign ovarian tumor. None of the patients with benign gynecological conditions had increased serum CA 15-3 levels. Serial measurements showed CA 15-3 concentrations to be correlated with the clinical behavior of disease in 21 of 25 patients (84%). CA 15-3 serum levels were also found to be correlated with findings on second look. These results suggest that CA 15-3 may represent a useful tumor marker in ovarian cancer.

Receptors for epidermal growth factor and steroid hormones in human breast cancer

Epidermal growth factor (EGF) seems to play an important role in regulating the proliferation of human breast cancer. Fifty-five primary breast tumors and 7 lymph node metastases were simultaneously assayed for the presence of EGF receptors (EGFR), estrogen receptors (ER), and progesterone receptors (PR). Overall, 42% (23/55) of the tumors were EGFR positive. EGFR were more frequently present in ER- and PR-negative than in ER- and PR-positive tumors. In particular, a negative correlation between EGFR and PR (chi 2 = 6.8; p greater than 0.01) was observed. All metastatic tumors were EGFR negative, and in all cases but 1 the levels of EGFR were higher in metastatic than in primary tumors. Our results suggest the presence of a subclass of breast tumors, the growth of which is primarily regulated by EGF or EGF-like substances rather than by steroid hormones. In this group, not amenable to endocrine therapy, EGF receptors should represent a target for therapeutic intervention.

Endometrial carcinoma: 128 cases at stages I and II

The authors have re-examined 146 patients with stage I and II endometrial carcinoma according to pathological findings. An understaging of FIGO classification of 9.8% and 14.2% in stages I and II, respectively, was found. Also evaluated was the influence of some risk factors (histologic grade, myometrial infiltration) on survival rates which was highly significant for both stages I and II. Surgery was the main form of treatment with an operability rate higher than 90%. The bilateral salpingo-oophorectomy appeared to improve the survival at stage I, 85.8% versus 63.6%, while postoperative external radiotherapy (ERT) seemed to be ineffective.

Estrogen responsive creatine kinase in human breast cancer cells

The brain type (BB) isoenzyme of creatine kinase (CK) is a very sensitive marker of estrogen action in rat uterus and in experimental mammary tumors. In order to detect useful markers for estrogen dependent human breast cancer cell proliferation we measured CK levels and isoenzyme composition in the CG5 cells, an estrogen supersensitive variant of the MCF-7 human breast cancer cell line. Under basal conditions, CK-BB accounted for 10%-15% of total enzymatic activity, while the MM isoenzyme represented the overwhelming component. In cells cultured in the presence of 5% charcoal-treated fetal calf serum, physiological concentrations (0.1-1 nM) of estradiol increased CK-BB levels in a dose- and time-related fashion. The effect was specific for estrogens and was prevented by antiestrogens. Our results show that CK-BB is estrogen regulated in the CG5 cells and suggest a possible role for this enzyme as an additional marker of the hormonal responsiveness of breast cancer.

Elevated plasma levels of beta-thromboglobulin in breast cancer

Beta-thromboglobulin, a platelet-specific protein secreted into the plasma during the release reaction, was measured in 73 women with breast cancer, 10 women with dysplastic disease and 30 healthy female control subjects. 73% of patients with primary operable breast cancer and 65% with metastatic disease had levels above 40 ng/ml (control range 11-38 ng/ml). Among 2-6 months' postoperative patients without evidence of disease at the time of sampling, beta-thromboglobulin was raised in 75% of patients with nodal involvement and in 28% of patients without nodal involvement. Only 1 of 10 patients with benign disease showed abnormal beta-thromboglobulin concentration. Our results show that in a high percentage of breast cancer patients a state of ongoing in vivo platelet activation may be present. Furthermore, beta-thromboglobulin can be regarded as a potential tumor marker in breast cancer.

Effect of tamoxifen on steroid hormone receptors and creatine kinase activity in human endometrial carcinoma

Estrogen receptor (ER), progesterone receptor (PR) and creatine kinase (CK) were measured in cancerous tissue from 29 post-menopausal patients with endometrial carcinoma under basal conditions and after a short course of tamoxifen treatment. ER and PR were detected in nearly all tumors. CK was detected in all of the tumors examined. After tamoxifen, PR and CK increased simultaneously in 26% of cases, while they were either enhanced, decreased or unmodified in the remainder. No correlation could be found between increase of PR and tumor differentiation. CK, however, was enhanced only in the more differentiated cancers. These results indicate that only a percentage of endometrial cancers are responsive to tamoxifen. It is hypothesized that patients bearing these tumors are those likely to benefit from endocrine therapy.

A monoclonal antibody (AB/3) reactive with human breast cancer

Monoclonal antibody AB/3 was produced from a fusion of spleen cells of a human breast cancer cell-primed BALB/c mouse with the murine myeloma cell line P3-NS1-Ag4-1. The antibody reacted strongly with the plasma membrane of human breast cancer cells. Tissue sections of both malignant and benign human mammary carcinomas and tumors of non-breast origin as well as apparently normal tissues were tested with immunoperoxidase. Ninety-six of 124 (77%) primary human breast cancers, 12 of 14 (86%) metastatic breast lesions, and 12 of 44 (27%) benign breast lesions reacted positively. Little or no appreciable reactivity was observed with apparently normal human tissues and carcinomas of non-breast origin, with the exception of colon carcinoma. Antibody AB/3 did not immunoprecipitate any identifiable protein from radiolabeled extracts of the immunizing cell line.

Sex steroid receptors in normal and malignant human vulvar tissue

Receptors for estrogens, progesterone and androgens were assayed in 6 specimens of normal vulvar tissue and in 9 specimens of carcinomatous vulvar tissue. These receptors were not always present in all specimens examined. In both normal and carcinomatous tissues receptor concentration was highly variable. Malignant tissues did not show significant changes in values compared to normal tissue.

Effects of intra-amniotic isoxsuprine on amino acid placental transfer in rats

Direct administration of isoxsuprine to the rat fetus increases placental transfer of 35S-methionine and this increase is statistically significant on day 17 as compared with intraperitoneal administration and controls (p less than 0.01; p less than 0.05). In contrast, no statistically significant differences were found between the groups on day 16.

Estrogen-responsive creatine-kinase in the reticulo-epithelial cells of rat thymus

We have evaluated the presence of the so-called "estrogen-induced protein" (IP) in the thymus of immature rat. IP is one of the earliest proteins synthesized in response to estrogen in rat uterus and has recently been identified as the BB-isozyme of creatine-kinase (J. Biol. Chem. 256 (1981) 5741). Estrogen-exposed tissues were labelled with [35S]methionine and the soluble proteins separated by SDS-polyacrylamide gel electrophoresis followed by fluorography. It was observed that estrogen stimulated the labelling of a thymic protein with electrophoretic mobility identical to that of uterine IP. The effect was dose-related and specific for estrogen receptor ligands. Thymic IP, like that of the uterus, was immunoprecipitated equally well by either anti-IP antiserum from rat uterus or anti-BB-creatine-kinase antiserum from rat brain. After purification by ion-exchange and affinity chromatography, there was a parallel increase in the extent of recovery of IP and BB-creatine-kinase activity in both the thymus and the uterus. Using the immunohistochemical peroxidase-antiperoxidase method with anti-IP serum, the immune-reaction product was localized in a few cells identified as reticulo-epithelial cells. The thymocytes were always free of any reaction product. These data demonstrate that the reticulo-epithelial cells of rat thymus are a target for estrogens.

Creatine kinase BB in normal, hyperplastic and neoplastic endometrium

We measured creatine kinase BB activity in normal, hyperplastic and neoplastic endometrium. Creatine kinase BB levels were higher in secretory than in proliferative endometrium. High levels were also found in hyperplastic tissue. In endometrial cancer creatine kinase BB activity was higher in well differentiated than in poorly differentiated tumors.

Estrogen stimulates cell proliferation and the increase of a 52,000 dalton glycoprotein in human breast cancer cells

In an estrogen supersensitive variant of the MCF-7 cell line, CG-5, estrogen was found to stimulate the labelling of a glycoprotein released into the culture medium which has the same electrophoretic migration pattern as that previously reported in MCF-7 cells (Biochem. Biophys. Res. Commun., 90: 410-416, 1979). To test the possibility that the 52 K is a marker of estrogen-dependent breast cancer cell proliferation, we have correlated the effect of estrogen and antiestrogen on protein labelling and cell proliferation under different experimental conditions. In cells cultured in the presence of 5% charcoal-treated fetal calf serum, physiological concentrations (0.1-1 nM) of estradiol stimulated in a dose- and time-related fashion both 52 K labelling and cell proliferation. However at high concentrations (10-100 nM) estrogen decreased 52 K labelling while it still stimulated cell proliferation. Concentrations of the tamoxifen derivative, 4-hydroxytamoxifen, which effectively prevented estrogen-stimulated cell proliferation also blocked estrogen-stimulated increase of 52 K labelling. Time-course experiments suggest that the estrogen-stimulated increase of 52 K labelling (detectable after 22 h of hormone exposure) precedes the effect of cell proliferation (detectable after 3 days of hormone exposure). In cells cultured under serum-free conditions there was no effect of estradiol at any of the concentrations and times used on either 52 K labelling or cell proliferation.

Steroid-induced proteins in human endometrium

The synthesis of soluble proteins in human endometria at various phases of menstrual cycle was evaluated by polyacrylamide gel electrophoresis of [35S]methionine-labeled proteins. Densitometric analysis of the gels revealed alterations in the rate of synthesis of single protein bands throughout the cycle. Administration of conjugated estrogens (Premarin) to women undergoing hysterectomy, or exposure, in vitro, of the endometrial tissue to 17 beta-estradiol produced an increased incorporation of [35S]methionine into a specific protein which migrated on SDS-polyacrylamide gels at a molecular weight of about 55 000. Induction of this protein was observed only in those endometria showing a secretory histological appearance. The protein was resolved into at least 2 different spots in two-dimensional gel electrophoresis. An increase in the rate of synthesis of another endometrial protein with an apparent molecular weight of 51 000 was observed in tissues exposed in vitro to medroxyprogesterone acetate. These steroid-induced proteins may be a useful marker for studying hormone action in both normal and neoplastic endometria.