Activity of cysteine proteases and their inhibitors in the lymph nodes of larynx cancer patients.
BACKGROUND
Cysteine endopeptidases and their inhibitors play an important role in the process of carcinogenesis. Positive correlation has been found between tumor invasiveness, its metastatic potential and the secretion of cysteine endopeptidases. Cysteine protease inhibitory activity is also altered in malignant tumors and various body fluids of patients with cancer.


METHODS
Total cysteine endopeptidase activity and cysteine proteinase inhibitory activity were measured in homogenates of cervical lymph node tissue surgically obtained from the larynx of cancer patients. The tissue samples were histologically examined, and each was divided into two parts: positive (PCN), with mostly cancer cells, and negative (NCN), with no cancer cells.


RESULTS
In the PCNs, the levels of the assayed enzymes and their inhibitors were significantly higher than in the NCNs. The mean values of cysteine protease activity were 2.70I2.29 and 1.59I1.28 for PCNs and NCNs, respectively (p<0.005). The mean values of cysteine protease inhibitors were 9.1I8.6 and 6.1I6.3 for PCNs and NCNs, respectively (p<0.02). An altered protease-inhibitor activity ratio was also found in PCN samples compared to NCNs.


CONCLUSIONS
These data suggest increased activity of cysteine peptidases and their inhibitors in the case of secondary tumor tissue. The cancer cells metastasized to lymph node tissue produce some alteration in balance between cysteine protease activity and the endogenous inhibitors of the proteases.
Siewiński
Maciej
M
Department of Medical Biochemistry, Medical University of Wrocław, Poland.
Berdowska
Izabela
I
Mikulewicz
Wojciech
W
Wnukiewicz
Jan
J
Gutowicz
Jan
J
D003546:Cysteine Endopeptidases / Q000378:metabolism*; D015853:Cysteine Proteinase Inhibitors / Q000378:metabolism*; D006801:Humans; D007822:Laryngeal Neoplasms / Q000209:etiology / Q000378:metabolism*; D008198:Lymph Nodes / Q000378:metabolism*; D008207:Lymphatic Metastasis
D015853:Cysteine Proteinase Inhibitors; D003546:Cysteine Endopeptidases