Immunohistochemical localization of group II phospholipase A2 in the tumours and mucosa of the colon and rectum.
BACKGROUND
Group II phospholipase A(2)(PLA(2)) is an enzyme important in malignant transformation and in the invasion process of malignant cells. The aim of the present study was to investigate the expression of group II PLA(2)in the cancers of the colorectum, peritumoural mucosa and in the mucosa distant from the tumour.


METHODS
Resection specimens from 57 patients with colorectal carcinoma (caecum 10, ascending 10, transverse 10, sigmoid colon nine, and rectum 18) were analysed immunohistochemically. Histological slides from paraffin blocks were stained by the human monoclonal group II PLA(2)antibody ('Upstate Biotechnology', Lake Placid, NY 12946, USA. Antibody Class: IgG1k. Immunogen: HPC purifed human sperm phospholipase A(2)- 14 kDa enzyme) using the standard DAKO peroxidase-labelled streptavidin-biotin method by TechMate 500 stainer. Group II PLA(2)expression was evaluated semi-quantitatively according to the extensivity and intensivity of the positive cells. For statistical evaluation the Kruskal-Wallis one way analysis of variance on ranks and the Mann-Whitney rank sum tests were used.


RESULTS
The highest expression of group II PLA(2)was found in the peritumoural mucosa (median 4.00), much lower in the mucosa distal from the tumour (median 0.70) and almost no activity in the tumour itself (median 0.00), all differences were statistically significant (all pairwise multiple comparison procedures - Dunn's Method P<0.05). The expression of group II PLA(2)was higher in the left colon and rectum than in the right colon (Mann-Whitney rank sum test P<0.05).


CONCLUSIONS
Our results suggest that there is variation of the group II PLA(2)expression throughout the mucosa and tumours of the colorectum, which might reflect the progression of neoplastic process.
Edhemović
I
I
Department of Surgical Oncology, Institute of Oncology Ljubljana, Zaloska 2, 1000 Ljubljana, Slovenia. ibrahim.edhemovic@mf.uni-lj.si
Snoj
M
M
Kljun
A
A
Golouh
R
R
D000704:Analysis of Variance; D014408:Biomarkers, Tumor / Q000032:analysis*; D001707:Biopsy, Needle; D015179:Colorectal Neoplasms / Q000201:enzymology* / Q000473:pathology*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007413:Intestinal Mucosa / Q000201:enzymology* / Q000473:pathology*; D008297:Male; D009367:Neoplasm Staging; D010741:Phospholipases A / Q000378:metabolism*; D054467:Phospholipases A2; D011336:Probability; D011379:Prognosis; D012680:Sensitivity and Specificity; D018709:Statistics, Nonparametric
D014408:Biomarkers, Tumor; D010741:Phospholipases A; D054467:Phospholipases A2