[Immunoscore and Its Predictive Value for Colorectal Cancer]

Recent studies suggest that immune  classification (immune-score) in cancer patients has a prognostic value in some cases that seems to be superior to the AJCC/ UICC TNM  classification. The clinical outcome can vary significantly among patients with a particular diagnosis within the same TNM stage. Immunoscore methodology quantifies and detects different types of immune cells in tumor tissue, and also determines the density of their infiltration and localization at the tumor site. Currently within an international collaboration of 23 centers in 17 countries (including our department), immunoscore is being evaluated in more than 7,000 colorectal cancer patients in terms of the tumor microenvironment, focusing on the presence of immune cells both in the tumor tissue and the tumor invasive margin. Immunoscore results are assessed in correlation with: 1. patients response to the treatment, 2. rate of progression, disease prognosis and other immune parameters. It appears that the TNM classification and tumor invasiveness is statistically dependent on the immune response of the patient (there is an inverse correlation between the density of the infiltration of CD8⁺, CD3⁺ lymphocytes and the tumor stage). High densities of T-lymphocytes (CD8⁺, CD3⁺) both in the core and the invasive margin of the primary tumor are associated with longer term asymptomatic survival, overall survival, lower risk of relapse and reduced likelihood of metastases. The project of the international collaboration aims to introduce immunoscore in routine diagnostics.

Pregnane xenobiotic receptors and their effect on drug elimination from the organism

Nuclear receptors are intracellular proteins which, having been activated by their more or less specific ligands, regulate (usually increase) the transcription of target genes. They thus participate in a regulation of a number of physiologic functions. Some of them - especially pregnane xenobiotic receptors - serve primarily as protection of the organism from the xenobiotic intoxication. This is because many xenobiotics activate their function which consists in increasing the gene expression of enzymes involved in the metabolism of xenobiotics and detoxication drug transporters. Clarification of these mechanisms enabled the understanding of the substance of many drug-drug interactions observed in the clinical practice. Polymorphism of the nuclear receptors appears to be one of the causes of the interindividual variability in response to drug administration.

Local treatment of hand-foot syndrome with uridine/thymidine: in vitro appraisal on a human keratinocyte cell line HaCaT

5-fluorouracil (5-FU) is one of the most commonly used antineoplastic drugs in the anticancer therapy. The hand-foot (HF) syndrome (palmar-plantar erythrodysesthesia) is an adverse effect frequently related to long-term i.v. administration of 5-FU or its orally applicable prodrug capecitabine. Its severity can even lead to interruption of the otherwise effective anticancer therapy. Tentative practice in some clinics has shown that topical application of 10% uridine ointment is beneficial for calming down the HF syndrome. This study is focused on verifying the alleged protective activity of uridine in the in vitro model of cultured human keratinocyte cell line HaCaT. We also tested the protective effects of thymidine alone or uridine-thymidine combination. The cellular viability time progression was measured in order to evaluate the effect of protective agents by three different types of cytopathogenicity tests-NTCA test (non-destructive test of cellular activity), modified MTT test and RTCA (real-time cell analyser, Roche). All three methods proved the ability of uridine and uridine-thymidine combination to protect keratinocytes against 5-FU damage in vitro. While thymidine alone did not show any remarkable effect, the thymidine-uridine combination demonstrated enhanced protective activity compared to uridine alone. Our findings provided the supporting rationale for using uridine or uridine-thymidine ointments in the HF syndrome local therapy.

Proteinase-activated receptor-2 expression in breast cancer and the role of trypsin on growth and metabolism of breast cancer cell line MDA MB-231

Proteinase-activated receptor-2 (PAR-2) is a ubiquitous surface molecule participating in many biological processes. It belongs to the family of G protein-coupled receptors activated by the site-specific proteolysis of trypsin and similar proteases. Altered function of PAR-2 has been described in different malignant tumors. In the present study, we investigated the expression of PAR-2 in breast cancer surgical specimens and the role of trypsin in breast cancer cell line MDA MB-231 proliferation and metabolism. A total of 40 surgical samples of infiltrative ductal breast cancer and breast cancer cell line were included in this study. We analyzed PAR-2 expression by immunohistochemistry, RT-PCR and western blot. Activation of PAR-2 on cell line MDA MB-231 was measured using calcium mobilization assay determined by flow cytometry. MTT cell metabolism assay and cell count analysis were used to assess the trypsin influence on breast cancer cell line MDA MB-231 proliferation. Immunohistochemical examination showed the expression of PAR-2 in all samples of breast cancer surgical specimens and high levels of cell lines which was confirmed by RT-PCR and western blot. Calcium mobilization assay corroborated the activation of PAR-2 on cell line MDA MB-231 either by trypsin or by an agonistic peptide. Cell metabolism assay and cell count analysis showed significant differences of proliferative activity of breast cancer cells dependent on the presence or absence of trypsin and serum in the culture medium. PAR-2 is expressed by high levels in infiltrative ductal breast cancer tissue specimens. PAR-2 is also strongly expressed in studied breast cancer cell lines. PAR-2 is activated by trypsin and also by agonistic peptide in the model of breast cancer cell line MDA MB-231. Activation of PAR-2 in vitro influences proliferative and metabolic activity of breast cancer cell line MDA MB-231. The action of trypsin is modified by the presence of serum which is a potential source of protease inhibitors.

Thymidine kinase in malignant melanoma

Thymidine kinase (EC 2.7.1.21) is an enzyme supporting DNA synthesis under conditions of increased cell proliferation. Although it has proved to be a useful marker for various malignant diseases, it has not been tested in malignant melanoma. Thymidine kinase activity was measured by means of a radioenzymic assay in two classical animal models of melanoma disease--B16 and Cloudman S91 melanoma-bearing mice. Tumour cell proliferation was assessed histochemically by measuring the expression of proliferating cell nuclear antigen (PCNA). Tumour cytosolic specific thymidine kinase activity was found to be higher in less pigmented Cloudman S91 melanoma than in differentiated, ie pigmented B16 melanoma, relative to the proliferative activity of the two tumours. Serum thymidine kinase levels were increased in melanoma-bearing animals of both types compared with healthy mice; this also reflected the efficacy of the therapy: cyclophosphamide-treated B16 melanoma-bearing mice in which the tumour development was slowed down had significantly lower serum enzyme levels in comparison with the non-treated group and the same levels compared with control, healthy mice. Our results suggest that serum thymidine kinase levels might be used as a marker to follow the effect of melanoma therapy.