Marcatori biomolecolari dei carcinomi del colon-retto sporadici ed ereditari

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1 Marcatori biomolecolari dei carcinomi del colon-retto sporadici ed ereditari Milo Frattini XII Congresso AIFEG Villa Cagnola - Gazzada Schianno (VA) 16/

2 APC β-catenina APC Met (p16) Models of tumor progression for CRC APC Met (p16) K-RAS APC Met (p16) K-RAS DCC APC Met (p16) K-RAS DCC p53 Hyperproliferation Type I adenoma Type II adenoma In situ carcinoma Metastasis APC β-catenina MMR genes (MLH1, MSH2,...) TGFβRII, BAX, BRAF IGF-IIR, E2F4, TCF-4 Hyperproliferation Type I adenoma Type II adenoma In situ carcinoma Metastasis

3 Harari et al, J Clin Oncol 2007;25: EGFR downstream pathway

4 Microsatellite instability

5 Microsatellites...AAAAAAAAAAAAAAAAAAAAA.. (mononucleotide repeat) CACACACACACACACACACA (dinucleotide repeat)

6 Microsatellite Instability (MSI): evaluation 1998 Bethesda Consensus Conference 5 mono- and di-nucleotides loci: BAT25, BAT26 / D2S123, D5S346, D17S Proposal of a new panel 5 mononucleotides loci: BAT25, BAT26, NR21, NR24 and NR27

7 Diversi sistemi multiproteici Mismatch cooperano Repair per (MMR) riparare genes eventuali danni al DNA...

8 Microsatellites and CRC Lynch Syndrome: 20% Sporadic: 80%

9 Lynch syndrome Patient < 50 yo with a CRC Genetic counselling Surgery MSI analysis Therapy IHC for MMR proteins Germline mutations of MMR genes

10 MMR: hereditary vs sporadic CRC 2nd mutational hit Hereditary ~ 20% Normal mucosa -> Adenoma -> Adenocarcinoma Heterozygous MMR gene mutation Sporadic ~ 80% MLH1 silencing Normal mucosa -> Serrated Adenoma -> Serrated adenocarcinoma

11 MSI and prognosis in CRC 13 studies in the literature In 11 studies there is a significant correlation between better prognosis and MSI (with respect to MSI-L/MSS)

12 MSI and adjuvant therapy

13 BRAF

14 BRAF pathway EGFR out cytoplasm PI3K K-Ras PTEN Akt mtor BRAF MEK ERK1,2 cell survival angiogenesis changes in gene expression nucleus cell proliferation tumor invasion tumor metastasization

15 BRAF: hereditary vs sporadic CRC 2nd mutational hit Hereditary ~ 20% Normal mucosa -> Adenoma -> Adenocarcinoma Heterozygous MMR gene mutation ~ 0% mutazione BRAF V600E Sporadic MLH1 silencing ~ 80% Normal mucosa -> Serrated Adenoma -> Serrated adenocarcinoma ~ 50% mutazione BRAF V600E

16 Lynch syndrome role of BRAF Patient < 50 yo with a CRC Genetic counselling Surgery MSI analysis Therapy IHC for MMR proteins BRAF mutation Germline mutations of MMR genes

17 BRAF in sporadic cases

18 PIK3CA

19 PIK3CA pathway EGFR out cytoplasm PI3K K-Ras PTEN Akt mtor BRAF MEK ERK1,2 cell survival angiogenesis changes in gene expression nucleus cell proliferation tumor invasion tumor metastasization

20 (Liao et al, 2012) PIK3CA and NSAIDs

21 (Cathomas et al, 2014) PIK3CA and NSAIDs

22 PIK3CA and NSAIDs

23 NSAIDs and FAP

24 Metastatic cases

25 EGFR downstream pathways EGFR out cytoplasm mutated in ~20% of sporadic CRC mutated in ~30-40% of sporadic CRC PI3K K-Ras loss in ~30% of sporadic CRC PTEN Akt BRAF MEK mutated in ~5-10% of sporadic CRC mtor ERK1,2 cell survival angiogenesis changes in gene expression nucleus cell proliferation tumor invasion tumor metastasization

26 EGFR downstream pathways EGFR out cytoplasm PTEN PI3K Akt mtor X KRAS XBRAF MEK ERK1,2 cell survival angiogenesis changes in gene expression nucleus cell proliferation tumor invasion tumor metastasization

27 KRAS status and clinical response Panit. BSC K-Ras mutations associated with cetuximab/panitumumab resistance and account for about 40% of NR patients (Amado et al, 2008) KRAS mut KRAS wt

28 (Custodio et al, 2013) KRAS mutations: meta-analysis

29 RAS: structure and functions Gene cod12 cod13 cod61 KRAS GGT (Gly) GGC (Gly) CAA (Gln) NRAS GGT (Gly) GGT (Gly) CAA (Gln) HRAS GGC (Gly) GGT (Gly) CAG (Gln) (Smith et al, 2010) KRAS = NRAS = HRAS INT

30 RAS: structure and functions KRAS ~ NRAS (Haigis et al, 2008) KRAS NRAS

31 (Custodio et al, 2013) NRAS mutations

32 KRAS and NRAS mutations 17% (Douillard et al, 2013)

33 (Douillard et al, 2013) KRAS and NRAS mutations

34 (Patterson et al, 2013) RAS mutations

35 BRAF mutations and clinical response Wild-type Mutant BRAF 68/79 (86%) 11/79 (14%) * Responders 22/68 (32%) 0/11 (0%) Non-responders 46/68 (68%) 11/11 (100%) p<0.05, two-tailed Fisher s exact test BRAF mutations are associated with lack of response to MoAbs treatment in K-Ras wild-type tumors (Di Nicolantonio & Martini & Molinari et al, J Clin Oncol 2008;26: )

36 BRAF mutations and clinical response Sorafenib restores sensitivity to cetuximab in BRAF V600E resistant CRC cells Cetuximab and Sorafenib act sinergistically (Di Nicolantonio & Martini & Molinari et al, J Clin Oncol 2008;26: )

37 (Custodio et al, 2013) BRAF mutations and clinical response

38 PIK3CA mutations and clinical response Wild-type Mutant PIK3CA 95/110 (86%) 15/110 (14%) * Responders 22/95 (23%) 0/15 (0%) Non-responders 73/95 (77%) 15/15 (100%) p<0.001, two-tailed Fisher s exact test PIK3CA mutations are associated with lack of response to MoAbs treatment in mcrc (Sartore-Bianchi & Martini & Molinari et al, Cancer Res 2009;69: )

39 PIK3CA mutations and clinical response Exon 9 Exon 20 Specific PIK3CA mutations are associated with lack of response to MoAbs treatment in mcrc (Prenen et al, Clin Cancer Res 2009;15: ; Sartore-Bianchi & Martini & Molinari et al, Cancer Res 2009;69: )

40 Take home messages Marker Hereditary Sporadic MSI BRAF diagnosis of Lynch syndrome absent in Lynch syndrome good prognosis resistance to 5-FU worse prognosis PIK3CA unknown in FAP efficacy of NSAIDs Metastatic cases

41 Special thanks to Tiziana Venesio