CA-125, placental alkaline phosphatase and tissue polypeptide antigen as preoperative serum markers in ovarian carcinoma

D-amino acid-containing supramolecular nanofibers for potential cancer therapeutics

Nanostructures formed by peptides that self-assemble in water through non-covalent interactions have attracted considerable attention because peptides possess several unique advantages, such as modular design and easiness of synthesis, convenient modification with known functional motifs, good biocompatibility, low immunogenicity and toxicity, inherent biodegradability, and fast responses to a wide range of external stimuli. After about two decades of development, peptide-based supramolecular nanostructures have already shown great potentials in the fields of biomedicine. Among a range of biomedical applications, using such nanostructures for cancer therapy has attracted increased interests since cancer remains the major threat for human health. Comparing with L-peptides, nanostructures containing peptides made of D-amino acid (i.e., D-peptides) bear a unique advantage, biostability (i.e., resistance towards most of endogenous enzymes). The exploration of nanostructures containing D-amino acids, especially their biomedical applications, is still in its infancy. Herein we review the recent progress of D-amino acid-containing supramolecular nanofibers as an emerging class of biomaterials that exhibit unique features for the development of cancer therapeutics. In addition, we give a brief perspective about the challenges and promises in this research direction.

Clinical utility of cytokeratins as tumor markers

Cytokeratins, belonging to the intermediate filament (IF) protein family, are particularly useful tools in oncology diagnostics. At present, more than 20 different cytokeratins have been identified, of which cytokeratins 8, 18, and 19 are the most abundant in simple epithelial cells. Upon release from proliferating or apoptotic cells, cytokeratins provide useful markers for epithelial malignancies, distinctly reflecting ongoing cell activity. It appears that motifs in certain cytokeratins make them likely substrates for caspase degradation, and their subsequent release occurs during the intermediate events in apoptosis. The clinical value of determining soluble cytokeratin protein fragments in body fluids lies in the early detection of recurrence and the fast assessment of the efficacy of therapy response in epithelial cell carcinomas. The three most applied cytokeratin markers used in the clinic are tissue polypeptide antigen (TPA), tissue polypeptide specific antigen (TPS), and CYFRA 21-1. TPA is a broad spectrum test that measures cytokeratins 8, 18, and 19. TPS and CYFRA 21-1 assays are more specific and measure cytokeratin 18 and cytokeratin 19, respectively. By following patients with repeated testing during management, the oncologist may obtain critical information regarding the growth activity in symptomatic patients. Although their main use is to monitor treatment and evaluate response to therapy, early prognostic information particularly on tumor progression and metastasis formation is also provided for several types of cancers. Cytokeratin tumor markers can accurately predict disease status before conventional methods and offer a simple, noninvasive, cheap, and reliable tool for more efficient management.

ED(27) trophoblast-like cells isolated from first-trimester chorionic villi are genetically identical to HeLa cells yet exhibit a distinct phenotype

ED(27) trophoblast-like cells were prepared from human chorionic villus samples obtained at 9 weeks gestation and have been grown continuously in vitro without phenotypic drift for nearly a decade. These cells express many trophoblast markers, including cytokeratin, placental alkaline phosphatase (PLAP), secretion of 17beta-estradiol, and a microvillous apical surface. The ED(27) cell line is a useful model system for studies of placental cell biology and has been distributed to laboratories world-wide. However, experiments to investigate their relationship to primary villous cytotrophoblast have shown that these cells do not secrete detectable amounts of human chorionic gonadotropin in culture and, when digested with trypsin, disperse into individual cells. Furthermore, immunocytochemical studies demonstrated that, unlike villous cytotrophoblasts, ED(27) cells were immunoreactive with monoclonal antibodies recognizing some HLA Class I antigens. This was not HLA-G, however, as would be expected if these cells originated from extravillous cytotrophoblasts, but rather classical HLA-A, B which is thought not to be expressed by any trophoblast subpopulations. These inconsistencies prompted us to question the authenticity of the continuous cell line as it now exists. Genetic haplotype analysis using the polymerase chain reaction (PCR) revealed that ED(27) was genetically identically to the HeLa cell line. Inasmuch as HeLa cells have never been grown in the laboratory (DAK), the only possible origin of HeLa cell contamination of ED(27) cells was the WISH cell line, and further PCR analysis revealed that this cell line was also genetically identical to HeLa. Like ED(27) cells, HeLa cells and WISH cells synthesized small amounts of estrogen and were found to express PLAP and antigens recognized by the monoclonal antibodies ED822, directed against the syncytiotrophoblast, and J1B5 directed against villous cytotrophoblast. These results point out the need for adherence to rigorous and consistent quality control measures to assure the authenticity of cell lines used as in vitro model systems.

Elevated serum alkaline phosphatase may enable early diagnosis of ovarian cancer

A case of endometrioid ovarian carcinoma associated with elevated levels of serum placental-like alkaline phosphatase (PLAP) is presented. Two and a half years before a final diagnosis was made following explorative laparotomy, an incidental blood test revealed elevated alkaline phosphatase in the patient's serum. A thorough investigation for the source of this elevation was negative. Postoperative immunohistochemical staining of the tumor, showed diffuse stain with PLAP, along with gradual decline to normal values of serum total alkaline phosphatase. It is suggested, that whenever serum alkaline phosphatase is elevated due to unknown reason, an investigation including alkaline phosphatase isoenzymes, serum Ca-125, trans-vaginal pelvic sonogram and even diagnostic laparoscopy, should be considered in a search for early preclinical ovarian cancer.

Estimation of probability of malignancy using a logistic model combining physical examination, ultrasound, serum CA 125, and serum CA 72-4 in postmenopausal women with a pelvic mass: an international multicenter study

BACKGROUND

To assess the differential diagnostic potential of physical examination, ultrasound, the serum CA 125 assay, and serum CA 72-4 assay, and the contribution of each parameter to a logistic model predicting the probability of malignancy in postmenopausal patients presenting with a pelvic mass.

PATIENTS AND METHODS

In a multicenter, prospective study a total of 155 patients were evaluated preoperatively using a standard protocol for pelvic examination, transvaginal (occasionally additional abdominal) ultrasound, and serum CA 72-4 (cutoff level 3 U/ml) and CA 125 (cutoff level 35 U/ml).

RESULTS

Fifty-nine malignant (39%) and 92 benign (61%) pelvic tumors were found in addition to 4 borderline tumors (3%). Forty-three patients appeared to have ovarian carcinoma, FIGO Stage III or IV in 28 cases. Borderline tumors were excluded from the statistical calculations. The diagnostic accuracy of each single parameter, i.e., pelvic examination, ultrasound, and serum CA 125 and CA 72-4 in discriminating between benign and malignant pelvic masses gave highly similar results (81, 76, 78, and 81% respectively). Best sensitivity was found in pelvic examination (92%); best specificity was found in CA 72-4 (93%). Using logistic regression analysis the power of pelvic examination appeared to be the most relevant (adjusted odds ratio 12.1), followed by ultrasound (odds ratio 9.7), serum CA 125 (odds ratio 5.0), and serum CA 72-4 (odds ratio 4.9). Age appeared to be nonpredictive. The logistic model gives a correct prediction in 87% of all cases.

CONCLUSIONS

The addition of serum CA 72-4 to the combination of pelvic examination, ultrasound, and serum CA 125 leads to an improved discrimination between malignant and benign pelvic masses.

Ovarian carcinoma serum markers and ovarian steroid activity--is there a link in ovarian cancer? A correlation of inhibin, tetranectin and CA-125 to ovarian activity and the gonadotropin levels

In a previous study, we have demonstrated that inhibin-production may be associated with improved survival and, also, that tetranectin (TN) is a valuable prognostic marker in ovarian epithelial cancer. We investigated the possible correlation between inhibin, tetranectin, CA-125, ovarian steroid activity and the gonadotropin levels. Preoperative serum levels of the tumor markers inhibin, tetranectin (TN) and CA-125 were measured and related to ovarian steroid function and the pituitary-gonadal axis (gonadotropin levels) in 28 postmenopausal ovarian cancer patients. The following median levels and 95% confidence limits were demonstrated for the tumor markers: Inhibin 0.4 U/l (0.2-0.9), TN 8.9 mg/l (6.8-9.2), CA-125 160 kU/l (75-687). A significant inverse correlation was demonstrated between inhibin and the gonadotropins. The Spearman correlation coefficients showed a highly significant correlation of inhibin with the examined ovarian steroid hormones except DHEAS which also has a suprarenal component. This indicates a synthesis of inhibin and the steroid hormones from the same cell compartment as known from the normal ovary and an apparently intact negative feed back mechanism. Inhibin may be produced in the normal ovary as a defense mechanism against an elevated gonadotropin level and inhibin acts by lowering the gonadotropins or by altering their biological activity. Elevated values of the tumor markers TN and CA-125 due to gonadotropin stimulation could not be demonstrated but a significant inverse correlation between TN and CA-125 was confirmed.

Immunohistochemical expression of placental alkaline phosphatase and vimentin in epithelial ovarian neoplasms

The immunohistochemical expression of PLAP and vimentin was assessed in 23 benign, 6 borderline malignant and 31 malignant epithelial ovarian neoplasms. PLAP and vimentin were expressed in some benign (3/23 and 5/23 respectively) and borderline malignant (2/6 for both markers) tumours and they were often expressed in malignant tumours (16/31 and 17/31 respectively). There was a significantly increased expression of PLAP and vimentin in serous cystadenomas and serous carcinomas compared to their mucinous counterparts. Although there was no significant correlation between PLAP expression and histologic grade of carcinomas there was a trend towards increased expression in more differentiated carcinomas. No correlation was found between vimentin expression and degree of differentiation.