Comparison of flow cytometric DNA content analysis in fresh and paraffin-embedded ovarian neoplasms: a prospective study

Targeting Colorectal Cancer Cell Lines Using Nanobodies; AgSK1as a Potential Target

Background: Colorectal cancer is the third most common type of aggressive cancers. Chemotherapy, surgery, and radiotherapy are the common therapeutic options for treating this cancer. Due to the adverse side-effects of these methods, immunotherapy is considered as an appropriate alternative therapeutic option. Treatment through the application of monoclonal antibodies is considered as a novel alternative therapeutic method for cancers. The variable fragments of the antibodies' heavy chain or VHHs have a wide application in molecular biology and biotechnology. VHHs are compatible with the phage display technology which allows rapid and high throughput screening for antibodies isolation. Objectives: We aimed to use naive VHH phage library to isolate a specific nanobody against colorectal tumor associated antigen; the AgSK1. Materials and Methods: In this research, naive VHH phage library was panned against two colorectal cell lines; Ls174T and HT29 expressing different levels of AgSK1 tumor associated marker. The high affinity binders were selected and subcloned for higher expression levels of the VHH. The affinity and specificity of the isolated VHH were tested using ELISA. The reactivity of the VHH toward cancer cells was analyzed by competitive ELISA applying sera isolated from colorectal cancer patients. Results: Results show that the isolated VHH recognizes and binds to the colorectal cancer cells with a high affinity. Moreover, the isolated nanobody is able to compete with the antibodies in the patient sera for the binding to the cancer cells. Conclusions: Results suggest that this nanobody has a specific reaction toward colorectal cells and can be used for further investigation on the tumor associated antigens or production of mimotopes useful for immunotherapy.

Real-time PCR hTERT mRNA pattern in tumor core, edge, resection margin, and lymph nodes in laryngeal tumors: relation to proliferative index and impact on prognosis

BACKGROUND

The immortalizing enzyme, telomerase, has been linked to carcinogenesis and is being targeted as a novel molecular marker. This study investigated the pattern of human telomerase reverse transcriptase (hTERT) mRNA by real-time polymerase chain reaction (PCR) in tumor core, edge, and safety margin of laryngeal tumors and related lymph nodes, as well as their relation to the proliferative index (PI) and their impact on prognosis.

MATERIAL AND METHODS

This prospective study included 35 patients with laryngeal carcinoma who were surgically treated by total or partial laryngectomy. Collected tissues from tumor core, edge, resection margin, and lymph nodes were examined by flow cytometry and real-time PCR quantification of hTERT mRNA.

RESULTS

The PI showed a statistically significant difference between the contrasted parts (P = 0.04). The highest median for PI was found in the tumor edge samples (31.3), followed by the tumor core (27.5), the resection margin (21.4), and finally the lymph nodes (10.3). There was no significant difference with regard to the ploidy patterns or the synthetic phase fraction (SPF) among the different tissue parts. Real-time PCR hTERT mRNA patterns showed that the highest median for hTERT mRNA level (copies/mug RNA) was in the tumor core (70.5), followed by the tumor edge (36.5), the resection margin (17.3), and finally the lymph nodes (4.4). There was a statistically significant difference with regard to the hTERT mRNA patterns among the different tissue parts (P = 0.04). Tumor differentiation, tumor edge ploidy, and tumor edge hTERT levels were significantly different between survivors and non-survivors, while tumor core S-phase fraction and tumor core PI significantly altered the disease-free survival rate.

CONCLUSION

hTERT mRNA may potentially be used for molecular reevaluation of the safety margin for conservational laryngeal surgery, and as a prognostic factor for overall survival especially if determined in samples taken from the growing edge of tumors.

Deletions of p15 and p16 in schistosomal bladder cancer correlate with transforming growth factor-alpha expression

OBJECTIVES

Cell proliferation is stimulated by growth factors and inhibited by p15 and p16 gene products. We compared cell regulators, TGF-alpha, p15, and p16, in schistosomal and non-schistosomal bladder cancer to explore possible differences in their alterations between the two subtypes and their correlations with proliferation pattern [synthetic phase fraction (SPF)], DNA ploidy, and clinicopathological factors.

METHODS

Tumor tissue samples were obtained from 120 patients. Expressions of p15 and p16 genes were investigated by the polymerase chain reaction, while TGF-alpha protein expression was measured by an enzyme immunoassay (EIA) method.

RESULTS

Deletion of both p15 and p16 was observed in 62 and 46 bladder tumors, respectively. TGF-alpha was overexpressed in 64 bladder tumors. A highly significant association was observed between the two deleted genes and TGF-alpha positivity. Of the entire group, p15 and p16 alteration and positive TGF-alpha (> or =cutoff value) were significantly expressed in schistosomal bladder cancer (68.1%, 60.9%, and 65.2%), and squamous cell carcinoma type (SCC) (69.1%, 64.7% and 72.1%) compared to those with non-schistosomal bladder cancer (29.4%, 7.8%, and 37.3%) or transitional cell carcinoma (TCC) (28.8%, 3.8%, and 28.8), respectively. A significant association between p15 and p16 deletion and TGF-alpha positivity with high SPF, aneuploid DNA pattern, late stages, and high histological grades was also documented.

CONCLUSION

Alteration of p15 and p16 genes and overexpression of TGF-alpha appears to be an event in bladder cancer that occurs more frequently in schistosomal bladder cancer and SCC, and may play an important role in their development. These observations may provide insight into treatment guided by molecular changes.

Increased bcl-2 expression is associated with primary resistance to chemotherapy in human epithelial ovarian cancer

OBJECTIVE

bcl-2, an anti-apoptotic factor, has a role in the pathogenesis of ovarian cancer as well as in resistance to chemotherapy.

DESIGN AND METHODS

20 benign, and 26 malignant epithelial ovarian tissues were analyzed for bcl-2 protein and mutant p53 by enzyme-immunoassay (EIA). Flowcytometric analysis was also performed. Patients of malignant group were followed up to monitor overall survival and primary resistance to chemotherapy.

RESULTS

bcl-2 was significantly higher in malignant group than benign group (p < 0.001). A cutoff value was determined for bcl-2 (63.8 kU/g protein). At this cutoff, sensitivity is 80.7%, and specificity is 85%. Using chi square analysis, a significant correlation was found between bcl-2 and FIGO stage (p = 0.01), overall survival (p = 0.01), as well as primary resistance to chemotherapy (p = 0.03). By correlation coefficient analysis the relation between bcl-2 and synthetic phase fraction was highly significant (p = 0.002). Bcl-2, p53, and FIGO stage were significantly correlated to poor survival (p = 0.01) in univariate analysis. However, in multivariate analysis, only FIGO stage, and p53 were independent risk factors.

CONCLUSION

EIA could be a useful tool for investigating the prognostic value of bcl-2, and its possible prediction of platinum resistance in epithelial ovarian cancer. This might help in selecting patients for future anti-bcl-2 therapy.

Regulators of apoptosis in human breast cancer

OBJECTIVES

Apoptosis or programmed cell death represents a mechanism by which tumor cells with DNA damage can be deleted. Bcl-2 and p53 gene products have been both linked to apoptosis. Bcl-2 plays a role as an inhibitor of apoptosis that may extend the viability of cells containing genetic alterations and facilitate tumor progression. Mutant p53 has a similar effect. The purpose of this study was to investigate expression of bcl-2 in 70 malignant and 30 benign breast lesions using different methods (enzyme immunoassay, immunodot blot, Western blot) and to compare it with the established clinicopathological prognostic factors (age, tumor size, type, grade, lymph node status) and some molecular genetic markers in breast cancer.

RESULTS

bcl-2 and mutant p53 were highly expressed in breast cancer than benign breast lesions and aneuploidy was more frequently detected in malignant breast samples. No correlation could be observed between bcl-2 expression and node status, tumor size, differentiation, type, age at excision or mutant p53 expression. However, a strong positive associations were seen between bcl-2 and estrogen receptors (ER), DNA aneuploidy. Eighty-five percent of bcl-2 positive tumors were ER positive and 65% were aneuploid, while in bcl-2 negative tumors only 28% were ER positive and 37% were aneuploid.

CONCLUSIONS

The association seen between bcl-2 and ER raises the possibility that bcl-2 is an ER-regulated gene which suggests a potential important role for bcl-2 as a modulator of response to hormonal therapy in breast cancer. Monitoring hormonal therapy can easily be done by bcl-2 quantitative EIA method.

Quantitation of bcl-2 protein in bladder cancer tissue by enzyme immunoassay: comparison with Western blot and immunohistochemistry

Apoptosis (programmed cell death) and the genes regulating this process (e.g., bcl-2), have recently become a focus of interest in the study of cancer development and progression. We adapted and evaluated a new enzyme immunoassay method (EIA) for quanitifying bcl-2 in cell lysates. The range of detection of the assay was 5–400 kilounits/L with inter- and intraassay CVs of 5.5–9.2% and 5.0–8.8%, respectively. The recovery of added bcl-2 protein to cell lysates was 96–104%. The concordance rates with Western blotting and immunohistochemistry were 97.5% and 93.7%, respectively. Bcl-2 concentrations were measured in the cell lysate of bladder tumors. The amount of bcl-2 in 158 bladder cancer (mean rank, 71.3 kilounits/g protein; range, 8.4–324 kilounits/g protein), was significantly higher than in nondiseased bladder tissues distant to the tumors (mean rank, 31.5 kilounits/g protein; range, 5–54.9 kilounits/g protein), P = 0.00001. Bcl-2 expression was correlated to tumor proliferative capacity, which was measured by DNA flow cytometry as the percentage of cells in the synthetic phase of the cell cycle. The enzyme immunoassay provides a rapid, quantitative, and reliable technique for measurement of bcl-2 in tumor tissue. The detection of substantial amounts of bcl-2 in invasive tumors (compared with nondiseased tissues) suggests that the assay should be a useful tool for investigating the prognostic value of bcl-2 in bladder tumors and for selecting patients for future anti-bcl-2 therapy.