Genetic modulation of the Let-7 microRNA binding to KRAS 3'-untranslated region and survival of metastatic colorectal cancer patients treated with salvage cetuximab-irinotecan.
Pharmacogenomics J
; 10(5): 458-64, 2010 Oct.
Article
in En
| MEDLINE
| ID: mdl-20177422
ABSTRACT
There is increasing evidence that the Let-7 microRNA (miRNA) exerts an effect as a tumor suppressor by targeting the KRAS mRNA. The Let-7 complementary site (LCS6) T>G variant in the KRAS 3'-untranslated region weakens Let-7 binding. We analyzed whether the LCS6 variant may be clinically relevant to patients with metastatic colorectal cancer (MCRC) treated with anti-epidermal growth factor receptor (EGFR) therapy. LCS6 genotypes and KRAS/BRAF mutations were determined in the tumor DNA of 134 patients with MCRC who underwent salvage cetuximab-irinotecan therapy. There were 34 G-allele (T/G+G/G) carriers (25%) and 100 T/T genotype carriers (75%). G-allele carriers were significantly more frequent in the KRAS mutation group than in patients with KRAS wild type (P=0.004). In the 121 patients without BRAF V600E mutation, overall survival (OS) and progression-free survival (PFS) times were compared between carriers of the LCS6 G-allele genotypes and carriers of the wild-type T/T genotype. LCS6 G-allele carriers showed worse OS (P=0.001) and PFS (P=0.004) than T/T genotype carriers (confirmed in the multivariate model including the KRAS status). In the exploratory analysis of the 55 unresponsive patients with KRAS mutation, LCS6 G-allele carriers showed adverse OS and PFS times. These findings deserve additional investigations as they may open novel perspectives for the treatment of patients with MCRC.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Colorectal Neoplasms
/
Antineoplastic Combined Chemotherapy Protocols
/
Proto-Oncogene Proteins
/
Salvage Therapy
/
Ras Proteins
/
3' Untranslated Regions
/
MicroRNAs
Type of study:
Etiology_studies
/
Incidence_studies
/
Observational_studies
/
Prognostic_studies
/
Risk_factors_studies
Limits:
Adult
/
Aged
/
Female
/
Humans
/
Male
/
Middle aged
Language:
En
Journal:
Pharmacogenomics J
Journal subject:
BIOLOGIA MOLECULAR
/
FARMACOLOGIA
Year:
2010
Type:
Article
Affiliation country:
Italy