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Biomedical subjects

J Skrk

Publications and source records attributed to J Skrk.

40 records · Page 3Linked to original sources

Drug resistant tumor cells have increased levels of tumor markers for invasion and metastasis.

The association between drug-resistance and three markers for invasive capacity: cathepsin D (Cath D), urokinase type plasminogen activator (uPA) and inhibitor of plasminogen activator type 1 (PAI-1) was examined in nine cervical and laryngeal carcinoma cell lines resistant to different cytostatics. The level of Cath D was measured by solid phase two-site immunoradiometric assay, while uPA and PAI-1 concentrations were determined by use of ELISA. All drug resistant cell lines had increased concentration of cathepsin D. uPA levels were similar in parental and drug resistant cervical carcinoma cells, but significantly higher in all examined drug resistant laryngeal carcinoma cells. In cervical carcinoma cells, PAI-1 concentrations were similar in parental and cisplatin resistant, but significantly higher in doxorubicin resistant cells. In laryngeal carcinoma cells, no increase in concentrations of PAI-1 was determined in the three from five resistant cell lines. There was no uPA in conditioned medium of parental or drug resistant cells. PAI-1 was detected in conditioned medium. Its levels were significantly increased in the medium of two cervical and three laryngeal drug resistant carcinoma cells. Thus, our results suggest that drug-resistance may be accompanied by increased levels of tumor associated proteases and/or its inhibitor.

Antineoplastic Agents↗

Urokinase-type plasminogen activator, plasminogen activator inhibitor type 1 and cathepsin D: analysis of their prognostic significance in squamous cell carcinoma of the head and neck.

BACKGROUND: The aim of the study was to evaluate the prognostic significance of tumour and serum concentrations of urokinase-type plasminogen activator (uPA), its type 1 inhibitor (PAI-1) and cathepsin D (Cath D) in patients with squamous cell carcinoma of the head and neck (SCCHN). PATIENTS AND METHODS: Determinations of uPA and PAI-1 were made using enzyme-linked immunosorbent assays in tumour and serum samples of 47 and 32/47 patients, respectively. For the determination of tumour (94 patients) and serum (34/94 patients) Cath D concentrations, an immunoradiometric assay was used. RESULTS: In an univariate survival analysis, the risk of disease recurrence and SCCHN-related death was significantly higher in the patients with high uPA (P = 0.046, P = 0.010) tumours, compared to those with low uPA tumours. In addition, the high serum levels of uPA correlated positively with the rate of relapse (P = 0.007), but not with the mortality rate (P = 0.200). There was no statistically significant difference between low and high PAI-1 groups, regarding either tumour or serum concentration of the inhibitor, and between low and high Cath D tumours. Low Cath D serum levels appeared to be related to longer disease-free interval (P = 0.055), but not to disease-specific survival (P = 0.120). CONCLUSIONS: The tumour levels of uPA, as well as serum levels of uPA and Cath D could potentially predict the survival probability of patients with SCCHN. However, the strength of this association remains to be investigated on a larger and more homogeneous group of patients.

Adult↗

Drug-resistant human laryngeal carcinoma cells have increased levels of cathepsin B.

In our previous work we showed that the drug-resistance of cervical carcinoma, laryngeal carcinoma and glioblastoma cells may be accompanied by increased levels of tumor markers for invasion and metastasis (i.e. urokinase-type plasminogen activator, plasminogen activator inhibitor type 1, and/or cathepsin D). In the present study we examined the concentration of cathepsins B, L and H in three drug-resistant clones isolated from human laryngeal carcinoma (HEp2). The basal levels of cathepsins B, L and H were determined by enzyme linked immunoabsorbent assay (ELISA). Our results showed that all three clones had an increased level of cathepsin B (in two clones an almost 4-fold increase was determined). The level of cathepsin L was altered (increased) only in VK2 clone, while the levels of cathepsin H were similar in parental cells and drug-resistant clones. Thus, our results suggest that drug-resistance may be accompanied by an increased level of cathepsin B, i.e. tumor associated protease, involved in invasion and metastasis.

Biomarkers, Tumor↗