Relationship between blood group-A antigen expression and malignant potential in hamster pancreatic cancers

Prognostic Significance of Blood Group Antigen Expression of Tumor Tissue in Lung Cancer Patients

Aims and background

Many prognostic factors have been evaluated both for SCLC and NSCLC. The prognostic significance of blood group antigen expression of tumor tissues has been studied particularly in NSCLC, yielding divergent results. The aim of the present study was to investigate the prognostic value of the tumoral expression of blood group antigens ABH in lung cancer.

Methods

The presence of blood group antigens was assessed immunohistochemically in paraffin-embedded tumor samples from 92 patients diagnosed between 1996 and 1997. Monoclonal antibodies were used to detect blood group antigens.

Results

The median survival was longer in NSCLC patients whose tumors were positive for blood group antigen A (P = 0.009). Since the expression of blood group antigen A in tumor cells was limited to patients with type A or AB blood, survival analysis of these patients showed survival to be longer in non-small cell lung cancer patients with blood group antigen A-positive tumors (P = 0.0019).

Conclusions

Expression of blood group antigen A in tumor cells is an important, favorable prognostic factor in patients with non-small cell lung cancer, which could be useful to stratify patients with blood group A or AB according to possible outcome, and to guide therapeutic decision-making. The expression of blood group antigens ABH should be evaluated in larger series of lung cancer patients (including small and non-small cell lung cancer) with all blood types.

Relationship between ?Gal epitope expression and decrease of tumorigenicity in pancreatic adenocarcinoma model

The alphaGal epitope is a carbohydrate structure, Galalpha1,3Galbeta1,4GlcNAc-R, synthesized on glycoconjugates in many mammals by alpha1,3galactosyltransferase. Humans do not express this epitope and present in serum large amounts of naturally occuring antibodies, which recognize the alphaGal epitopes and participate in the hyperacute rejection of xenograft. Studies indicated that the fundamental mechanism of hyperacute rejection involving the alphaGal epitope expression can be used in cancer therapy. We have previously suggested that the alphaGal epitope expression by human pancreatic tumoral cells could decrease the tumorigenic behavior of these cells. To determine whether the expression of the alphaGal epitope can modify the tumorigenicity of pancreatic cancer cells, we used a Syrian golden hamster pancreatic adenocarcinoma experimental model. The expression of alphaGal epitopes in the Syrian golden hamster pancreatic cancer cell line HaP-T1 was obtained by selecting stable cell clones transfected with murine alpha1,3galactosyltransferase gene. The alphaGal epitope expression resulted in a delay in the tumoral development of HaP-T1 cells in vivo after allograft transplantation of Syrian golden hamsters (2.5-fold, P < 0.05) and of nude mice. This result is associated with an 100% increase in survival time of nude mice bearing tumors expressing the alphaGal epitope. Our results confirm that the cell surface expression of alphaGal epitope decreases the tumorigenic behavior of pancreatic cancer cells. This novel property may be useful for the development of cancer gene immunotherapy strategy.

Pancreatic cell lines: a review

Pancreatic cancer has an extremely poor prognosis and lacks early diagnostic and therapeutic possibilities, mainly because of its silent course and explosive fatal outcome. The histogenesis of the disease and early biochemical and genetic alterations surrounding carcinogenesis are still controversial. In vitro studies offer a useful tool to study physiologic, pathophysiologic, differentiation, and transformation processes of cells and to understand some of these shortcomings. The extreme difficulties in isolating individual pancreatic cells and their purification by maintaining their native characteristics have limited research in this area. This review is intended to present and discuss the current availability of rodent and pancreatic cell lines, their differences as well as the difficulties, limitations, and characteristics of these cultured cells. Discussed are in vitro models; ductal, islet, and acinar cell culture; cell differentiation; cell transformation, including genetic and chromosomal alterations; as well as tumor cell markers. Also addressed are the advantages and problems associated with the cell culture in humans and rodents. Advancements in tissue culture technique and molecular biology offer steady progress in this important line of research. The improved methods not only promise the establishment of beta-cell cultures for the treatment of diabetes, but also for studying sequential genetic alterations during pancreatic carcinogenesis and in understanding the tumor cell origin.

Modification of antigen expression in human and hamster pancreatic cancer cell lines induced by sodium butyrate

The effects of sodium butyrate (NaB) on the growth, morphology, and expression of blood group A, Lewis(a), and CA 19-9 antigen in the hamster pancreatic cancer cell lines, PC-1 (well differentiated) and PC-1.0 (poorly differentiated), and of blood group A, DU-PAN-2, and CA 19-9 antigens in four human pancreatic cancer cell lines, HPAF and CD11 (well differentiated) and CD18 and PANC-1 (poorly differentiated), were examined. NaB inhibited the growth of all cell lines and induced cell enlargement, an increase in secretory material, microfilaments, and pseudopodia. NaB stimulated the production of blood group A antigen in PC-1.0 cells dose dependently, but no change in the expression of this antigen was observed in the human cell lines. However, NaB treatment increased the presence of cells positive for CA 19-9 in PANC-1 but not in the remaining cell lines, none of which reacted with the anti-CA 19-9 antibody before or after NaB treatment. Untreated PANC-1 cells did not produce either blood group A or DU-PAN-2 antigen, but expressed these antigens after NaB treatment in a dose-dependent manner. The results suggest that NaB stimulates the differentiation of the hamster and human pancreatic cancer cell lines and increases or induces the expression of some tumor-associated antigens.