TUBITAK Grant No:SBAG-2567(102S045)

1. TUBITAK Grant No:SBAG-2567(102S045)

2. AsbestosUsageInTurkey • Interior of house plastered with asbestos-containing ‘white soil’. • Outdoors and floors of the same house plastered with asbestos-containing ‘white soil’.

3. Fairy Chimneys in Cappadocia

4. Erionite fibre From A. Umran Dogan • Houses constructed with bricks containing erionite fibres

6. INTRODUCTION Intrapleural inoculation of erionite displayed 300-800 and 100-500 times more carcinogenic activity than chrysotile and crocidolite respectively Carthew P, Hum Exp Toxicol 1992; 11: 530-4 Patients with erionite-induced MPM have significantly shorter life time. Hence, erionite induced cases have higher aneuploidy compared with asbestos induced cases (72.7% vs 13.8%) suggesting more aggressive tumor behavior. Emri S. Lung Cancer 2001; 33: 109-114

7. HYPOTHESIS Since erionite and asbestos induced MPM differs in biological behavior, their contributions of apoptotic pathways in tumor development could be different.

9. Mitochondrial pathway

10. Bcl-2 Prevents The Cancer Cell Death  Bcl-2/bax: Worse prognosis Advance tumor grade ↓Bcl-2/Bax :Lower tumor grade. Better prognosis Better treatment response

11. The Final Common Pathway Cytochrome c Fas –Fas L Caspase Activation Cell Death

12. AIM • Bcl 2/Bax and Fas/Fas L pathways were studied in vivo in a comparative manner in tissue sections from patients with erionite and asbestos induced MPM. • The association of expression pattern and survival has been evaluated. • Sections from adenocarcinoma served as control group.

13. MATERIAL AND METHOD 52 patients including 16 (30.7%) patients with erionite and 19 (36.5%) patients with asbestos induced MPM were enrolled in the study. Tissue samples from patients with adenocarcinoma [n=17 (32.6%)] served as control groups.

14. METHOD 2 • Immunohistochemicallysemiquantitative • thestaining extension expressing the percentages of positive cells/tissue section • the staining intensity0=null, 1=weak, 2=moderate and 3=strong.

15. Statistical Analysis • SPSS 10.01 for Windows (1999) was used for statistical analysis. Chi square, Fisher’s exact chi square, Kruskal Wallis ANOVA and, Mann Whitney U tests were performed for comparisons . • Survival analysis was done by Kaplan Meier Survival analysis • Prognostic factors were analysed by Cox’s Multivariate Regression Model.

16. RESULTS

20. Antibody Intensity Erionite MPM No (%) Asbestos MPM No (%) Adenocarcinoma No (%) Bcl-2 Null 14 (88) 18 (95) 17 (100) Weak 2 (13) 1 (5) 0 Fas Null 15 (94) 18 (95) 14 (82) Weak 1 (6) 0 3(18) Moderate 0 1(5) 0 Bax Null 10 (63) 12 (63) 8 (47) Weak 2 (13) 5 (26) 6 (35) Moderate 4 (25) 2 (11) 3 (18) Fas Ligand Null 4 (25) 2 (11) 1 (6) Weak 6 (38) 5 (26) 1 (6) Moderate 6 (38) 10 (53) 15 (88) Strong 0 2 (11) 0 BAX: 14 %, 5 %, 8 % Fas L: 27 %, 47 %, 26 %

21. Fig. 1: Sections with antibody stainings (X400). a)  Skin epidermis. Positive control for Fas antibody. The image shows positive staining.

22. Fig. 1: Sections with antibody stainings (X400). Section from sarcomatous type MPM (asbestos). Moderately intense staining with Fas Ligand antibody.

23. Fig. 1: Sections with antibody stainings (X400). Section from mixed type MPM (erionite). Moderately intense staining with Bax antibody.

24. Survival 1 The median survival time in erionite induced MPM (14 months) was similar to time in asbestosis induced MPM (14 months). Difference in median survival according to tumor stage, different treatment modalities and different histological subtypes was not statistically significant in whole MPM group.

25. Survival 2 In conjunction with antibody staining, Bax negative erionite patients had better survival (18 months) than bax positive erionite patients (14 months, OR: 18.83) This was not true for the asbestosis group. In Whole MPM group, Fas L positive patients (15 months) showed statistically better survival when compared to Fas L negative patients (12 months) (OR: 3.12, p=0.05) in whole MPM group

26. Patients with no Bax expression showed better survival than patients with Bax expression in erionite group (p=0.06).

27. Patients with Fas Ligand expression showed better survival than patients without expression in whole MPM group (p=0.05).

28. TARTIŞMA

29. This is the first study that compares common apoptotic protein expression in erionite and asbestos induced MPM. • As similar to previous studies, Bcl-2 expression was not showed in the MPM sections. This may imply that Bcl 2 does not take an important part in the pathogenesis of MPM. Narasimhan et al. Am J Physiol 1998.

30. Bax is a proapoptotic protein. We have shown that it expresses similarly in all groups. • A previous study has shown that Bax had extensively expressed in MPM cell lines. However, they concluded that Bax has been disfunctional in MPM. Narasimhan et al. Am J Physiol 1998.

31. There is only one study that investigate the relation of apoptotic protein expression and survival. • Accordingly, there is no relation of Bax and Bcl-2 and survival. • Soini Y et al. Clin Cancer Res 1999. • In our study, in only erionite group, Bax had been inversely related with survival.

32. Bax is a proapoptotic protein • RELATED WITH WORSE PROGNOSIS • Other antiapoptotic proteins may use this pathway to exert their activity • This finding indicates a possible different mechanism in apoptotic pathways in erionite group. • INDICATES FURTHER STUDIES IN CELL LINES

33. Stewart et al have shown that Fas/Fas L pathway may intact in MPM and may be enhanced by chemotherapeutics. • Stewart et al. J Thorac Cardiovasc Surg 2002. • In our study there is almost no expression of Fas expression. This was also true for adenocarcinoma. However, Fas L expressed heavily and showed better prognosis.

34. In Conclusion, • Bcl-2 may not involve in the tumorigenesis of MPM. • Bax expression was associated with poor prognosis in only erionite induced MPM. This may imply a difference in apoptotic behaviour in erionite and asbestos induced MPM. • Fas L pathway may be intact and may be associated with better survival in whole MPM group.