Isolation of blood-borne epithelium-derived c-erbB-2 oncoprotein-positive clustered cells from the peripheral blood of breast cancer patients

Clinical studies including thousands of breast cancer patients have shown that c-erbB-2 is amplified and overexpressed in 20-30% of invasive human breast cancers and that it is associated with distant metastasis in specified patient subgroups. To isolate and characterize hematogeneously spreading c-erbB-2-positive epithelium-derived cells from the peripheral blood of breast cancer patients, a combined buoyant density gradient and immuno-magnetic separation method has been used. The method utilizes a biotinylated anti-cytokeratin monoclonal antibody (MAb) for capturing the epithelium-derived cells. The expression of c-erbB-2 by the captured cells was detected using an anti-c-erbB-2 rabbit antibody (21N) coupled to an anti-rabbit gold-labeled anti-body, whereby immunoenzymatic cytokeratin staining was performed using a silver-enhanced immunogold double staining protocol. In total, 29 of the 46 patients tested had either cytokeratin (24/29) or cytokeratin/c-erbB-2 (19/29) positive clustered cells in their peripheral blood. We thus report here the presence and the frequency of clone-specifically stained clustered cells in the peripheral blood of breast cancer patients. The frequency of cytokeratin/c-erbB2 double-positive clustered cells in the peripheral blood was on average 10 times higher than that of double-positive single cells. The numbers of cytokeratin/c-erbB-2 double-positive clustered cells were positively correlated with the stage of tumors. Results of in vitro motility experiments using single and clustered cells from primary breast cancer tissue strongly support the assumption that cytokeratin/c-erbB-2 double-positive clustered cells have a high potential for locomotion. We suggest that blood-borne epithelium-derived c-erbB-2-positive clustered cells are the possible precursor cells responsible for the formation of distant metastases and bone marrow micrometastases.

Neovaginal cytology after total pelvic exenteration for gynecological malignancies

Vaginal reconstruction has become an established method to restore sexual function in women who have undergone ultraradical surgery and/or irradiation for the treatment of gynecologic malignancies. Cytologic evaluation of the neovagina serves a major role in the detection of recurrent disease. The purpose of this retrospective 6-yr study (January 1987-December 1993) was to evaluate the cytologic features of vaginal smear specimens from neovaginas constructed utilizing split-thickness skin grafts. Thirty-four vaginal smears were obtained at regular intervals from nine women (mean age: 51 yr) who underwent total pelvic exenteration with vaginal reconstruction for recurrent malignancies of the vagina and the cervix. Anucleated, keratinizing squames were a constant finding in each smear. Over a 4-mo-6-yr postoperative period, superficial and intermediate squamous cells were present in the majority of the smears and the maturation index showed a shift to the right. In two cases, a squamous cell carcinoma of the cervix recurred within the neovagina. Knowledge of the cytologic features associated with neovaginas is important in order to distinguish normal changes from neoplastic lesions.

Protein kinase C-dependent and -independent pathways mediate epidermal growth factor (EGF) effects in human endometrial adenocarcinoma cell line KLE

The role of EGF in the proliferation of the poorly differentiated endometrial adenocarcinoma cell line (KLE) was examined. EGF (10 ng/ml) and the tumor promoter, protein kinase C agonist, phorbol 12-myristate 13-acetate (PMA) were potent stimulators (P < 0.01) of DNA synthesis in this cell line as determined by [3H]thymidine incorporation into DNA. Staurosporine, a protein kinase C inhibitor, partially blocked the EGF effects on [3H]thymidine incorporation. Similarly, downregulation of protein kinase C also failed to completely abolish EGF effect on DNA synthesis and cell division. These results suggest that in the KLE cell line EGF stimulation of cell growth is exerted through both protein kinase C-dependent and -independent pathways.

Epidermal growth factor receptor expression in three different human endometrial cancer cell lines

BACKGROUND

The aim of the current study was to establish the characteristics of the epidermal growth factor (EGF) receptor in endometrial cell lines to determine the possible relation of EGF to endometrial cancer.

METHODS

Three different cell lines were used: RL95-2 (derived from a moderately differentiated adenosquamous carcinoma), HEC-I-A (from a moderately differentiated adenocarcinoma), and KLE (from a poorly differentiated adenocarcinoma). The binding of (125-I) EGF to these cell lines and the stimulatory effect of EGF on (3H) thymidine incorporation into DNA were examined.

RESULTS

EGF receptor was present in all three cell lines. The binding of 125-I-labeled EGF was saturable and of high affinity. Scatchard analysis of the competitive binding data for KLE, HEC-I-A, and RL95-2 revealed linear plots, indicating a single class of binding sites with almost identical equilibrium dissociation constants (0.34 nM, 0.23 nM, and 0.20 nM, respectively). Other peptides, such as insulin-like growth factor (IGF) I and II and insulin, did not compete for the receptor. RL95-2 cells bound significantly more EGF (P < 0.005) than did the HEC-I-A and KLE cell lines. EGF increased 3H-thymidine incorporation in all three cell lines.

CONCLUSION

Because EGF receptors are expressed by all three cell lines at markedly different levels and because EGF stimulates 3H-thymidine incorporation into DNA in the three cell lines, the current study suggests that EGF may play a role in the promotion of growth endometrial adenocarcinoma.

Growth fractions in breast cancers determined in situ with monoclonal antibody Ki-67

The growth fractions of 160 mammary carcinomas and 30 benign mammary lesions were determined in situ by immunostaining with the monoclonal antibody Ki-67. Benign lesions had a mean value of 3% Ki-67 positive cells, whereas the mean value of mammary carcinomas was 16.6%. A comparison of the mean values of Ki-67 positive cells with the histological grade of the tumours showed a correlation between these two variables--that is, histological grade 1 showed 9%, grade 2 16%, and grade 3 26% proliferating cells. Considering the individual Ki-67 values in the different histological grades, it was evident that there was considerable scatter in the number of proliferating cells, so that the proliferation rates of grades 1, 2, and 3 overlapped each other. This indicates a dissociation between histological grade of malignancy and size of the growth fraction in most breast cancers. Follow up studies are needed to establish which of the two variables--that is, morphological degree of malignancy, or the proportion of Ki-67 positive cells--correlates better with response to treatment and survival in individual cases.