Immunosuppressive activity of proteases in cervical carcinoma.
OBJECTIVE
The host immune response is essential for restraining both HPV infections and HPV-related cervical cancer. We previously reported a direct correlation between proteolytic activity and malignant progression from precursor lesions to invasive cervical carcinoma. The present study was undertaken to investigate whether proteinases from cervical carcinoma extracts and representative purified proteinases involved in tumor progression could regulate lymphocyte proliferation to phytohemagglutinin (PHA) mitogen.


METHODS
Extracts were prepared from tissue samples obtained from patients with invasive cervical squamous carcinoma, squamous intra-epithelial lesions or women with normal cervix. Lymphocytes obtained from a single healthy donor were pre-incubated with one of these extracts in the presence or absence of proteinase inhibitors, and stimulated with PHA during 72 h. The proliferative response was measured using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) method (re-validated with thymidine uptake).


RESULTS
Lymphocyte proliferation was significantly decreased by cervical carcinoma extracts, while only slightly decreased by squamous intra-epithelial lesions or normal extracts. Inhibitor assays indicated that proteinases from cervical carcinoma were responsible for 53.30% of total suppressive activity. We found that purified enzymes such as trypsin, cathepsin B, uPA and type IV collagenase suppressed the proliferative response in a dose-dependent fashion.


CONCLUSIONS
Our data suggest that in addition to the classic role in tumor invasion, proteases could represent an immune evasion mechanism in cervical carcinoma.
Daneri-Navarro
Adrian
A
Programa de Doctorado en Ciencias Biomédicas, Departamento de Fisiología, Centro Universitario de Ciencias de la Salud, Universidad de Guadalajara, 44340 Guadalajara, Jalisco, México. daneri@cucs.udg.mx
Del Toro-Arreola
Susana
S
Sanchez-Hernandez
Pedro Ernesto
PE
Ramirez-Dueñas
Maria Guadalupe
MG
Armendariz-Borunda
J
J
Perez-Montfort
Ruy
R
D002294:Carcinoma, Squamous Cell / Q000201:enzymology / Q000276:immunology / Q000473:pathology; D005260:Female; D006801:Humans; D007108:Immune Tolerance; D008213:Lymphocyte Activation / Q000187:drug effects; D009361:Neoplasm Invasiveness; D010447:Peptide Hydrolases / Q000276:immunology* / Q000378:metabolism; D010835:Phytohemagglutinins / Q000494:pharmacology; D011480:Protease Inhibitors / Q000494:pharmacology; D013601:T-Lymphocytes / Q000276:immunology; D002583:Uterine Cervical Neoplasms / Q000201:enzymology* / Q000276:immunology* / Q000473:pathology; D002578:Uterine Cervical Dysplasia / Q000201:enzymology* / Q000276:immunology* / Q000473:pathology
D010835:Phytohemagglutinins; D011480:Protease Inhibitors; D010447:Peptide Hydrolases