Epithelial markers in pancreatic carcinoma: immunoperoxidase localisation of DD9, CEA, EMA and CAM 5.2

Biomarker-Based Therapy in Pancreatic Ductal Adenocarcinoma: An Emerging Reality?

Over the last decade, many of the major solid organ cancers have seen improvements in survival due to development of novel therapeutics and corresponding biomarkers that predict treatment efficacy or resistance. In contrast, favorable outcomes remain challenging in pancreatic ductal adenocarcinoma (PDAC), in part related to the lack of validated biomarkers for patient and treatment selection and thus optimal clinical decision-making. Increasingly, however, therapeutic development for PDAC is accompanied by bioassays to evaluate response and to study mechanism of actions with a corresponding increase in the number of trials in mid to late stage with integrated biomarkers. In addition, blood-based biomarkers that provide a measure of disease activity and allow for minimally invasive tumor analyses are emerging, including circulating tumor DNA, exosomes, and circulating tumor cells. In this article, we review potential biomarkers for currently approved therapies as well as emerging biomarkers for therapeutics under development. Clin Cancer Res; 24(10); 2241-50. ©2017 AACR.

Identification of a novel subpopulation of tumor-initiating cells from gemcitabine-resistant pancreatic ductal adenocarcinoma patients

Pancreatic ductal adenocarcinoma is highly resistant to systemic chemotherapy. Although there are many reports using pancreatic cancer cells derived from patients who did not receive chemotherapy, characteristics of pancreatic cancer cells from chemotherapy-resistant patients remain unclear. In this study, we set out to establish a cancer cell line in disseminated cancer cells derived from gemcitabine-resistant pancreatic ductal adenocarcinoma patients. By use of in vitro co-culture system with stromal cells, we established a novel pancreatic tumor-initiating cell line. The cell line required its direct interaction with stromal cells for its in vitro clonogenic growth and passaging. Their direct interaction induced basal lamina-like extracellular matrix formation that maintained colony formation. The cell line expressed CD133 protein, which expression level changed autonomously and by culture conditions. These results demonstrated that there were novel pancreatic tumor-initiating cells that required direct interactions with stromal cells for their in vitro cultivation in gemcitabine-resistant pancreatic ductal adenocarcinoma. This cell line would help to develop novel therapies that enhance effects of gemcitabine or novel anti-cancer drugs.

A comprehensive characterization of pancreatic ductal carcinoma cell lines: towards the establishment of an in vitro research platform

There are a large number of stable pancreatic ductal carcinoma cell lines that are used by researchers worldwide. Detailed data about their differentiation status and growth features are, however, often lacking. We therefore attempted to classify commonly used pancreatic carcinoma cell lines according to defined cell biological criteria. Twelve pancreatic ductal adenocarcinoma cell lines were cultured as monolayers and spheroids and graded according to their ultrastructural features. The grading system was based on the integrity of membrane structures and on the presence of mucin granules, cell organelles, nuclear and cellular polymorphism, cell polarity, and lumen formation. On the basis of the resulting scores the cell lines were classified as well, moderately, or poorly differentiated. In addition, immunocytochemistry was performed for the markers cytokeratin 7, 8, 18, 19, carcinoembryonic antigen, MUC1 MUC2, MUC5, and MUC6. The population doubling time of monolayer cultures, determined by a tetrazolium salt based proliferation assay was correlated with the ultrastructural grade. The grading of the ultrastructural features of the monolayers, and particularly of the spheroids, revealed that Capan-1 and Capan-2 cells were well differentiated; Colo357, HPAF-2, Aspc-1, A818-4, BxPc3, and Panc89 cells were moderately differentiated and PancTu-I, Panc1, Pt45P1, and MiaPaCa-2 cells poorly differentiated. Membrane-bound MUC1 staining was a characteristic of well differentiated cell lines. The population doubling time of the monolayer cultures was related to the differentiation grade. No relationship was found between the p53, K-ras, DPC4/Smad4, or p16(INK4a) mutation status and the grade of differentiation. We conclude that the proposed ultrastructural grading system combined with the proliferative activity provides a basis for further comparative studies of pancreatic ductal adenocarcinoma cell lines.

Optimization of the immunohistochemical demonstration of keratins in paraffin wax-embedded mouse skin

The purpose of this study was to develop an immunoperoxidase technique for the detection of cytokeratins in samples of paraffin wax-embedded adult and fetal skin from NMRI mice, with various antibodies (Troma-1, LL001, 8.60, MCK5, MCK6, AF129) that have been tested mainly on fresh-frozen sections. Each antibody was tested with three different fixatives (10% neutral buffered formalin, Bouin's fluid, and 70% ethanol) and two distinct pretreatments (enzymatic digestion with trypsin, or heat treatment). The best results, in terms of non-specific background labelling, morphological preservation and intensity of specific labelling, were obtained (1) for adult skin, by the use of Bouin's fluid, heat pretreatment and antibodies LL001, MCK5, MCK6 or AF129, and (2) for fetal skin, by the use of 70% ethanol, heat pretreatment and antibody Troma-1. Monoclonal antibody 8.60 gave the best results when the use of 70% ethanol was combined with either enzymatic digestion or heat pretreatment.

Proliferating cell nuclear antigen (PCNA) in pancreatic adenocarcinoma

Interpretation of pancreatic biopsy material can pose substantial difficulties, particularly in the presence of chronic pancreatitis where ductular changes and fibrosis may mimic adenocarcinoma. We examined whether differences in cell kinetics could aid in the distinction between pancreatic carcinoma and chronic pancreatitis. Pancreatic tissue was obtained by percutaneous ultrasonographic guided biopsy. There were a total of thirty-four cases comprising patients with chronic pancreatitis (N = 11) and those with adenocarcinoma (N = 23). The cell cycle activity was determined in sections of routinely paraffin-processed, formalin-fixed biopsy material using immunohistochemical stains for the monoclonal proliferating cell nuclear antigen antibody PCNA (PC 10), a 36 kd nuclear protein synthesized in the late G 1 and S phase. After calculating the PCNA index (% of positively staining nuclei compared to total number of nuclei counted) these were compared in the conditions studied. The PCNA indices in chronic pancreatitis were low with a mean of 5%, while those of adenocarcinoma were 53% (p < 0.001). In conclusion, the PCNA index in pancreatic adenocarcinoma is significantly higher than in chronic pancreatitis. Determination of the PCNA index may be helpful as an adjunct in the diagnosis of problematic cases.

Use of tumour marker immunoreactivity to identify primary site of metastatic cancer

OBJECTIVES

To determine whether variations in the expression of tumour related antigens can predict the origin of tumours.

DESIGN

Immunohistological study of tumour marker expression in primary adenocarcinomas and respective metastatic deposits. Antibodies to the following tumour markers were used: polymorphic epithelial mucin (NCRC-11 and SM3), carcinoembryonic antigen, carcinoembryonic antigen with non-specific antigen co-specificity, CA125, CA19.9, prostate specific antigens, and thyroglobulin.

SETTING

Histopathology department of teaching hospital.

SUBJECTS

100 pathology sections of metastatic adenocarcinoma and their related primary tumours.

MAIN OUTCOME MEASURES

Concordance of reactivity between primary and metastatic tumours. Reactivity profiles of tumour sites.

RESULTS

The correct primary site of origin was predicted in 70% (33/47) of tumours in men and 54% (27/43) tumours in women with antibodies SM3, 288, CA19.9, CA125, and PSA (men only). Specificities ranged from 68% for breast tumour to 98% for prostate tumour.

CONCLUSION

Use of tumour markers in patients presenting with metastatic adenocarcinoma of unknown origin can help localise the probable primary sites and reduce the need for extensive and expensive imaging techniques.

TDM35--a new monoclonal antibody to the XH1 cervical carcinoma cell line. Characterization and immunoperoxidase localization in benign and malignant tissues

The murine monoclonal IgG1 kappa antibody TDM35 was raised against the cervical carcinoma cell line XH1. The antibody recognizes 18.5-66 kDa NCA-like glycoproteins and immunostains a variety of formalin-fixed, paraffin-embedded normal, benign, and malignant tissues. It is of value in the diagnosis of carcinoma of the exocrine pancreas and it identifies foci of squamous and glandular differentiation in other tumours. TDM35 should form a useful addition to a panel of antibodies for the evaluation of epithelial lesions.

The immunoperoxidase localization of tumour markers in ovarian cancer: the value of CEA, EMA, cytokeratin and DD9

Primary tumours from 40 patients with epithelial ovarian cancer, treated at St Thomas's Hospital over a 10-year period, were studied for the immunocytochemical expression of the following tumour markers in formalin-fixed paraffin embedded material: carcinoembryonic antigen (CEA), epithelial membrane antigen (EMA), cytokeratin (CAM 5.2), and DD9. An indirect immunoperoxidase staining technique was used. All of the tumours were positive for EMA and CAM 5.2, and 30% of them were positive for both CEA and DD9. The absence of CEA and DD9 may be of value in differentiating between metastatic abdominal adenocarcinomas of ovarian origin and those of gastrointestinal origin, but no indication of prognosis was obtained using these epithelial markers. The strong and widespread staining of all the tumours for EMA suggests that this may be a useful marker for detecting metastatic or recurrent disease by immunoscintigraphy.