VUmc. VU University Medical Center, Amsterdam, The Netherlands University of Pisa, Pisa, Italy

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1 MicroRNA-21 (mir-21) in pancreatic adenocarcinoma: correlation with clinical outcome and pharmacological aspects underlying its role in the modulation of gemcitabine activity Elisa Giovannetti, Niccola Funel, Ayse Erozenci, Marco Del Chiaro, Leticia G. Leon, Enrico Vasile, Luca E. Pollina, Annemieke Groen, Alfredo Falcone, Daniela Campani, Ugo Boggi, Henk M. Verheul, Romano Danesi, Godefridus J. Peters VUmc VU University Medical Center, Amsterdam, The Netherlands University of Pisa, Pisa, Italy

2 Pancreatic Ductal Adenocarcinoma (PDAC) PDAC is the most lethal of the common cancers! Early metastatic spread! Local/metastatic recurrence! Multifactorial resistance to treatments! Lack of biomarkers to select targeted treaments New biomarkers/strategies for maximizing therapeutic efficacy and minimizing useless treatment in PDAC patients are urgently warranted

3 Micro-RNA A class of small non-coding RNAs that interact with the mrnas of coding genes to direct their post-transcriptional repression A booming field in cancer biology as:! Oncogenes/tumor suppressor genes! Diagnostic biomarkers! Prognostic biomarkers! Determinants of chemoresistance! Potential therapeutic targets Creation of Adam - Michelangelo detail with small variation

4 Aim To characterize mir-21 expression in a wide repository of PDAC tissues and cells, and evaluate the association with clinical outcome and gemcitabine activity

5 Patients and methods 77 consecutive pancreatic cancer patients underwent surgical procedures consisting of pancreatico-duodenectomy, distal or total pancreatectomy or biopsy Laser microdissection of frozen tumor tissues with Leica AS/LMD instrument Adjuvant or palliative chemotherapy with gemcitabine 1000 mg/m2 Follow-up Response to treatment was evaluated using the RECIST criteria, while the Kaplan-Meier method was used to plot DFS, TTP and OS RNA extraction Quantitative RT-PCR analysis of mir-21 Analysis of the association of clinical and pathological factors and mir-21 by "Log-rank test (OS, PFS and DFS curves) "Cox proportional hazard multivariate

6 Laser microdissection

7 ... not only PDAC tissues Micro- and non-microdissected PDAC specimens 8 primary cultures (+ 7 ATCC cell lines) Pancreas Normal pancreatic tissues Islet cells Acinar cells Ductal cells 5 normal LMD-ductal tissues (+ htert-hpne ductal pancreatic immortalized cells and Hs27 fibroblasts)

8 Results: mir-21 expression mir- 21 expression (ΔCt vs. RNU43) inoperable/ metasta/c N=77 LMD samples PDAC samples adjuvant normal ductal samples mir- 21 expression (ΔCt vs. RNU43) microdissected N=10 non- micro dissected PDAC samples mir- 21 expression (ΔCt vs. RNU43) Inoperable/metasta>c (N=12) and adjuvant (N=44) G1 G2 G3 PDAC (WHO) grading P=0.014 P=0.034

9 Results: correlation with outcome In the inoperable/metastatic setting (N=32)! Trend toward a significant association with clinical benefit = PR+SD (P=0.07)! Significant association with PFS and OS 100 P= low mir- 21 high mir- 21 Progression probability % Survival probability % P= Time (months) Time (months)

10 Results: correlation with outcome In the adjuvant setting! Significant association with DFS (P=0.004) and OS (P=0.009) In the inoperable/metastatic + adjuvant setting (N=58)! Significant association with OS Survival probability % low mir-21 high mir Time (months)! Multivariate analysis indicated that adjuvant setting of therapy and high mir-21 expression were independent predictors of prognosis (HR=0.3, with P<0.001 for adjuvant setting, and HR=2.6, with P=0.001 for high mir-21 expression, respectively)

11 ... one more ride Preclinical studies on the role of mir-21:! Cytotoxicity / apoptosis! PTEN/Akt expression/phosphorylation! Expression of MMP-2/-9

12 Gemcitabine cytotoxicity and basal mir-21 expression Fibroblasts htert- HPNE LPC111 LPC167 LPC067 MIA PaCa- 2 HPAF- II BxPc3 Gemcitabine cytotoxicity (IC50) nm mir- 21 expression (ΔCt vs. RNU- 43) LPC006 LPC033 LPC028 Primary cell cultures >ssues cells P=0.003 PP437 LPC067 LPC167 LPC111 PP437 LPC028 HPAC LPC033 Capan- 2 PANC- 1 LPC006 PL mir- 21 expression (ΔCt normalized to RNU- 43) Gemcitabine cytotoxicity (IC50) nm P=0.032 mir-21 below median mir-21 above median

13 Modulation of gemcitabine cytotoxicity and apoptosis Cells transfected with Pre-miR LPc028 - transfected control pre-mir LPc028 - transfected pre-mir-21 LPc111 - transfected control pre-mir LPc111 - transfected pre-mir-21 % Cell growth vs. control (Gemcitabine)nM Apoptotic index (%) Control pre-mir Control+anti-miR-21 Control+pre-miR Gemcitabine pre-mir Gemcitabine+anti-miR-21 Gemcitabine+pre-miR-21 P<0.05 vs. Gemcitabine P<0.01 vs. Gemcitabine LPc067 LPc028

14 Krichevsky and Gabriely, 2009 mir-21 targets and its regulatory network

15 PTEN expression and its modulation by pre-mir-21 7 PDAC tumors with mir-21 expression above median: PTEN expression -/+ 7 PDAC tumors with mir-21 expression below median: PTEN expression ++/+++ LPc067 LPc028 PTEN β-actin Control pre-mir pre-mir-21 Control pre-mir pre-mir-21

16 mir-21 Modulation of Akt phosphorylation pakt/total Akt (U/ng) Cells transfected with pre-mir Cells transfected with pre-mir-21 P<0.05 vs. Gemcitabine+pre-miR # P<0.05 vs. Gemcitabine+pre-miR-21 # 0.0 LPc Apoptotic index (%) # Cells transfected with pre-mir Cells transfected with pre-mir-21 P<0.05 vs. Gemcitabine+pre-miR # P<0.05 vs. Gemcitabine+pre-miR-21 0 Treatments

17 Other targets: MPM-2/-9 and VEGF mrnaexpression (ΔΔCt vs. β-actin and control cells) modulation vs. control cells % control 0 0 LPc067 LPc028 LPc067 LPc028 mrna protein MMP-2 MMP-9 VEGF LPc067 P<0.05 vs. control

18 Conclusions! MiR-21 expression was correlated with clinical outcome in patients with PDAC both in the adjuvant and in the palliative setting! Preclinical studies showed that mir-21 expression in primary cultures correlated with expression in their respective tissues, and with gemcitabine resistance in all the PDAC cells! Modulation of apoptosis, PTEN expression, Akt phosphorylation, and expression of genes involved in invasive behaviour, may contribute to mir-21 role in gemcitabine chemoresistance The consistency of the accumulating preclinical and clinical data suggest that PDAC are more aggressive and resistant to gemcitabine if they have high expression of mir-21, which therefore represents a promising target for prognostic and therapeutic approaches