To evaluate whether the epidermal growth factor receptor (EGFR), K-Ras and PTEN, all members of the EGFR signalling pathway, may affect the clinical response in cetuximab-treated metastatic ...colorectal cancer (mCRC) patients. Twenty-seven cetuximab-treated mCRC patients were evaluated for drug response and investigated for EGFR protein expression and gene status, K-Ras mutational status and PTEN protein expression. Ten patients achieved a partial response (PR) to cetuximab-based therapy. All 27 patients showed EGFR protein overexpression. Epidermal growth factor receptor gene amplification was observed in eight out of 27 (30%) and chromosome 7 marked polysomy in 16 (59%) patients. Partial response was observed in six out of eight patients with EGFR gene amplification, four out of 16 with marked polysomy and none out of three with eusomy (P<0.05). The K-Ras wild-type sequence was observed in 17 patients, and nine of them experienced a PR. Conversely, K-Ras was mutated in 10 cases, of which one patient experienced a PR (P<0.05). The PTEN protein was normally expressed in 16 patients, and 10 of them achieved a PR. In contrast, no benefit was documented in 11 patients with loss of PTEN activity (P<0.001). Patients with EGFR gene amplification or chromosome 7 marked polysomy respond to cetuximab. In addition to K-Ras mutations, we demonstrate for the first time that the loss of PTEN protein expression is associated with nonresponsiveness to cetuximab.
Background: It has been reported that KRAS mutations (and to a lesser extent KRAS mutations with the BRAF V600E mutation) negatively affect response to anti-epidermal growth factor receptor (EGFR) ...mAbs in metastatic colorectal cancer (mCRC) patients, while the biological impact of the EGFR pathway represented by PI3K/PTEN/AKT on anti-EGFR treatment is still not clear.
Patients and methods: We analysed formalin-fixed samples from a cohort of 32 mCRC patients treated with cetuximab by means of EGFR immunohistochemistry, EGFR and PTEN FISH analysis, and KRAS, BRAF, PI3KCA, and PTEN genomic sequencing.
Results: Ten (31%) of 32 patients showed a partial response to cetuximab and 22 (69%) did not nonresponder (NR). EGFR immunophenotype and FISH-based gene status did not predict an anti-EGFR mAb response, whereas KRAS mutations (24%) and PI3K pathway activation, by means of PI3KCA mutations (13%) or PTEN mutation (10%)/loss (13%), were significantly restricted to, respectively, 41% and 37% of NRs.
Conclusion: These findings suggested that KRAS mutations and PI3KCA/PTEN deregulation significantly correlate with resistance to cetuximab. In line with this, patients carrying KRAS mutations or with activated PI3K profiles can benefit from targeted treatments only by switching off molecules belonging to the downstream signalling of activated EGFR, such as mammalian target of rapamycin.
In metastatic colorectal cancer (mCRC), KRAS is the only validated biomarker used to select patients for administration of epidermal growth factor receptor (EGFR)-targeted therapies. To identify ...additional predictive markers, we investigated the importance of HER2, the primary EGFR dimerisation partner, in this particular disease.
We evaluated the HER2 gene status by fluorescence in situ hybridisation (FISH) in 170 KRAS wild-type mCRC patients treated with cetuximab or panitumumab.
Depending on HER2 gene copy number status, patients showed three distinct cytogenetic profiles: 4% of patients had HER2 gene amplification (R:HER2/CEP17 ≥ 2) in all neoplastic cells (HER2-all-A), 61% of patients had HER2 gain due to polysomy or to gene amplification in minor clones (HER2-FISH+*), and 35% of patients had no or slight HER2 gain (HER2-FISH-). These subgroups were significantly correlated with different clinical behaviours, in terms of response rate (RR; P=0.0006), progression-free survival (PFS; P<0.0001) and overall survival (OS; P<0.0001). Patients with HER2-all-A profile experienced the worst outcome, patients with HER2-FISH- profile showed an intermediate behaviour and patients with HER2-FISH+* profile were related to the highest survival probability (median PFS in months: 2.5 vs 3.9 vs 7.6, respectively; median OS in months: 4.2 vs 9.7 vs 13, respectively).
HER2 gene copy number status may influence the clinical response to anti-EGFR-targeted therapy in mCRC patients.
This study aimed to contribute to the accurate taxonomic delimitation of
Lippia origanoides
Kunth (Verbenaceae), an important native Brazilian herb with diverse medicinal properties, culinary uses ...and wide phenotypic plasticity. For this purpose, the large-scale in vitro propagation of accessions of
L. origanoides
, initially identified as
L. microphylla
(two accessions),
L. sidoides
and
L. salviaefolia
, was established. In addition, the composition of the three major volatile organic terpenes in these accessions was compared. The micropropagation protocols revealed differences in the proliferative responses of the different accessions; in contrast, there was a predominance of the terpenes thymol, thymol methyl ether and thujopsene in the volatile organic fraction, regardless of the
Lippia
accession evaluated. The correlation analyses grouped the two
L. microphylla
accessions in poles opposite to the other two accessions (
L. sidoides
and
L. salviaefolia
), but multivariate principal component analysis (PCA) considering the major terpenes present in the organic fraction grouped the four accessions near the center of the PCA, indicating similarity among them. The results of this study demonstrated that
L. origanoides
can be efficiently propagated in vitro. Furthermore, based on the results of the analysis of the composition of major terpenes and molecular markers, the main contribution of the present study was to corroborate the hypothesis that the dissimilarity among the evaluated
Lippia
accessions is insufficient for them to constitute distinct species and that they are therefore synonymous with
L. origanoides
.
Key Message
L. origanoides
plants can be efficiently micropropagated, and molecular markers and the proportion of major terpenes present in its essential oil can be used in the taxonomic delimitation of the species.
AKT1(E17K) in human solid tumours Bleeker, F E; Felicioni, L; Buttitta, F ...
Oncogene,
2008-Sep-18, 20080918, Letnik:
27, Številka:
42
Journal Article
Recenzirano
The serine-threonine kinase AKT1 is a central player in the oncogenic pathway controlled by PI3K. Recently, a somatic mutation in AKT1 (E17K) has been detected in breast, colorectal, lung and ovarian ...cancers. The E17K change results in constitutive AKT1 activation and induces leukaemia in mice. We determined the occurrence of the E17K variant in a panel of 764 tumour samples. These included breast, lung, ovarian, colorectal and pancreatic carcinomas as well as melanomas and glioblastomas. Despite the fact that these tumours are known to bear alterations in genes involved in the PI3K signalling pathway, AKT1(E17K) was detected only in breast (16/273), colorectal (1/88) and lung (1/155) cancers. Within the neoplasms of breast origin, the AKT1(E17K) variant was mutually exclusive with respect to the PIK3CA(E454K or H1047R) alleles and was present only in ductal and lobular histotypes. Our results, showing that AKT1 mutations seem to occur in a tissue-specific fashion have basic and clinical implications. First, the activity of mutated AKT1 in oncogenic PI3K signalling could be strictly dependent on the cell and tissue milieu. Second, therapeutic efforts aimed at selective targeting the AKT1(E17K) variant could be effective mainly in specific cancer types.
Abstract Because plasma DNA may be a useful tool for cancer detection, we screened primary tumors and related multiple plasma samples at the time of surgery and during the follow-up period for plasma ...DNA level as well as for K-Ras mutations and p16 INK4a promoter hypermethylation in colorectal cancer patients. At the time of surgery, DNA levels were higher in tumor patients than in healthy donors, and K-Ras and p16 INK4a alterations were detected in 7 and 11 cancers respectively, and in all related plasma samples. During the follow-up, plasma DNA levels decrease progressively but rapidly increased when a relapse occurred, whereas K-Ras and p16 INK4a alterations were detected only in relapsed patients. Therefore, combined quantitative and qualitative analyses of plasma DNA confirm the presence of colorectal cancer, define disease-free status and indicate the presence of relapse.
Cetuximab and panitumumab efficacy in metastatic colorectal cancer (mCRC) may be influenced by EGFR gene status and/or deregulation of its downstream signalling proteins detected in primary tumour. ...However, metastasis might have different molecular patterns with respect to primary tumour, possibly affecting the prediction of EGFR-targeted therapy efficacy. We analysed primary tumour and metastasis in 38 mCRC patients. Twelve cases were cetuximab/panitumumab treated. EGFR gene status and protein expression were investigated through fluorescent in situ hybridisation and immunohistochemistry (IHC), K-Ras/BRAF mutations by sequencing and PTEN expression by IHC. We observed EGFR gene deregulation in 25 out of 36 primary tumours and 29 out of 36 metastases, K-Ras mutations in 16 out of 37 cancers and in 15 out of 37 metastases, BRAF mutations in 2 out of 36 cancers and 2 out of 36 metastases and PTEN loss in 8 out of 38 cancers and 12 out of 38 metastases. For the first time in literature, we show that primary colorectal cancer and paired metastasis may exhibit difference with respect to EGFR pathway deregulation mechanisms possibly implying a different response to cetuximab or panitumumab treatment. The investigation of treated patients confirms this hypothesis. We therefore suggest that the analysis of metastatic lesion should be considered in patient management as well as in designing future clinical trials aimed to investigate the effect of anti-EGFR monoclonal antibodies in the treatment of mCRC.
The growing consumption of low- and reduced-fat dairy products demands routine control of their authenticity by health agencies. The usual analyses of fat in dairy products are very simple laboratory ...methods; however, they require manipulation and use of reagents of a corrosive nature, such as sulfuric acid, to break the chemical bounds between fat and proteins. Additionally, they generate chemical residues that require an appropriate destination. In this work, the use of an artificial neural network based on simple instrumental analyses, such as pH, color, and hardness (inputs) is proposed for the classification of commercial yogurts in the low- and reduced-fat categories (outputs). A total of 108 strawberry-flavored yogurts (48 probiotic low-fat, 36 low-fat, and 24 full-fat yogurts) belonging to several commercial brands and from different batches were used in this research. The statistical analysis showed different features for each yogurt category; thus, a database was built and a neural model was trained with the Levenberg-Marquardt algorithm by using the neural network toolbox of the software MATLAB 7.0.1. Validation with unseen data pairs showed that the proposed model was 100% efficient. Because the instrumental analyses do not require any sample preparation and do not produce any chemical residues, the proposed procedure is a fast and interesting approach to monitoring the authenticity of these products.
Our aim was to investigate the prognostic and predictive value of the oncogenic MAPKK-like protein T-cell-originated protein kinase (TOPK) stratified by KRAS and BRAF mutations in patients with ...sporadic, hereditary and metastatic colorectal cancer (CRC) treated with anti-EGFR therapy.
Immunohistochemistry (IHC) for TOPK was performed on four study groups. Group 1 included two subgroups of 543 and 501 sporadic CRC patients used to test the reliability of TOPK expression by IHC. In Group 2, representing an additional 222 sporadic CRCs, the prognostic effect of TOPK stratified by KRAS and BRAF was assessed. The prognostic effect of TOPK was further analysed in Group 3, representing 71 hereditary Lynch syndrome-associated CRC patients. In Group 4, the predictive and prognostic value of TOPK was analysed on 45 metastatic patients treated with cetuximab or panitumumab stratified by KRAS and BRAF gene status.
In both sporadic CRC subgroups (Group 1), associations of diffuse TOPK expression with clinicopathological features were reproducible. Molecular analysis of sporadic CRCs in Group 2 showed that diffuse TOPK expression was associated with KRAS and BRAF mutations (p<0.001) and with poor outcome in patients with either mutation in univariate and multivariate analysis (P=0.017). In hereditary patients (Group 3), diffuse TOPK was linked to advanced pT stage. In metastatic patients treated with anti-EGFR therapy (Group 4), diffuse TOPK expression was linked to dismal outcome despite objective response to treatment (P=0.01).
TOPK expression is an unfavourable prognostic indicator in sporadic patients with KRAS or BRAF mutations and also in patients with metastatic disease experiencing a response to anti-EGFR therapies. The inhibition of TOPK, which could benefit 30-40% of CRC patients, may represent a new avenue of investigation for targeted therapy.
The in vitro Cell Transformation Assay (CTA) is a powerful tool for mechanistic studies of carcinogenesis. The endpoint is the classification of transformed colonies (foci) by means of standard ...morphological features. To increase throughput and reliability of CTAs, one of the suggested follow-up activities is to exploit the comprehension of the mechanisms underlying cell transformation. To this end, we have performed CTAs testing CdCl2, a widespread environmental contaminant classified as a human carcinogen with the underlying mechanisms of action not completely understood. We have isolated and re-seeded the cells at the end (6weeks) of in vitro CTAs to further identify the biochemical pathways underlying the transformed phenotype of foci. Morphological evaluations and proliferative assays confirmed the loss of contact-inhibition and the higher proliferative rate of transformed clones. The biochemical analysis of EGFR pathway revealed that, despite the same initial carcinogenic stimulus (1μM CdCl2 for 24h), transformed clones are characterized by the activation of two different molecular pathways: proliferation (Erk activation) or survival (Akt activation). Our preliminary results on molecular characterization of cell clones from different foci could be exploited for CTAs improvement, supporting the comprehension of the in vivo process and complementing the morphological evaluation of foci.
PDF
