[Show abstract][Hide abstract] ABSTRACT: Introduction:
KRAS oncogene mutations (MUTKRAS) drive resistance to EGFR inhibition by providing alternative signaling as demonstrated in colo-rectal cancer. In non-small cell lung cancer (NSCLC), the efficacy of treatment with EGFR tyrosine kinase inhibitors (EGFR-TKIs) depends on activating EGFR mutations (MUTEGFR). However, inhibition of EGFR may select resistant cells displaying alternative signaling, i.e., KRAS, or restoration of EGFR activity due to additional MUTEGFR, i.e., the c.2369C > T (p.T790MEGFR).
The aim of this study was to investigate the appearance of MUTKRAS during EGFR-TKI treatment and their contribution to drug resistance.
This study used cell-free circulating tumor DNA (cftDNA) to evaluate the appearance of codon 12 MUTKRAS and p.T790MEGFR mutations in 33 advanced NSCLC patients progressing after an EGFR-TKI.
p.T790MEGFR was detected in 11 (33.3%) patients, MUTKRAS at codon 12 in 3 (9.1%) while both p.T790MEGFR and MUTKRAS codon 12 were found in 13 (39.4%) patients. Six patients (18.2%) were KRAS wild-type (WTKRAS) and negative for p.T790MEGFR. In 8 subjects paired tumor re-biopsy/plasma samples were available; the percent concordance of tissue/plasma was 62.5% for p.T790MEGFR and 37.5% for MUTKRAS. The analysis of time to progression (TTP) and overall survival (OS) in WTKRAS vs. MUTKRAS were not statistically different, even if there was a better survival with WTKRAS vs. MUTKRAS, i.e., TTP 14.4 vs. 11.4 months (p = 0.97) and OS 40.2 vs. 35.0 months (p = 0.56), respectively.
MUTKRAS could be an additional mechanism of escape from EGFR-TKI inhibition and cftDNA is a feasible approach to monitor the molecular development of drug resistance.
[Show abstract][Hide abstract] ABSTRACT: MNNG HOS transforming gene (MET) is a class IV receptor tyrosine kinase, expressed on the surface of epithelial cells. The interaction with the hepatocyte grow factor (HGF) induces MET dimerization and the activation of multiple intracellular pathways leading to cell proliferation, anti-apoptosis, morphogenic differentiation, motility, invasion, and angiogenesis. Knock out mice have demonstrated that MET is necessary for normal embryogenesis including the formation of striate muscles, liver and trophoblastic structures. The overexpression of MET and HGF are common in solid tumors and contribute to determine their growth. Indeed, MET has been cloned as a transforming gene from a chemically induced human osteosarcoma cell line and therefore is considered a proto-oncogene. Germline MET mutations are characteristic of hereditary papillary kidney cancers and MET amplification is observed in tumors including lung and gastric adenocarcinomas. The inhibition of MET signaling is the target for specific drugs that are raising exciting expectation for medical treatment of cancer.
[Show abstract][Hide abstract] ABSTRACT: Genetic alterations and etiology of thymic epithelial tumors (TETs) are largely unknown, hampering the development of effective targeted therapies for patients with TETs. Here TETs of advanced-stage patients enrolled in a clinical trial of molecularly-guided targeted therapies were employed for targeted sequencing of 197 cancer-associated genes. Comparative sequence analysis of 78 TET/blood paired samples obtained from 47 thymic carcinoma (TC) and 31 thymoma patients revealed a total of 86 somatic non-synonymous sequence variations across 39 different genes in 33 (42%) TETs. TCs (62%; 29/47) showed higher incidence of somatic non-synonymous mutations than thymomas (13%; 4/31; p < 0.0001). TP53 was the most frequently mutated gene in TETs (n = 13; 17%), especially in TCs (26%), and was associated with a poorer overall survival (p < 0.0001). Genes in histone modification [BAP1 (n = 6; 13%), SETD2 (n = 5; 11%), ASXL1 (n = 2; 4%)], chromatin remodeling [SMARCA4 (n = 2; 4%)], and DNA methylation [DNMT3A (n = 3; 7%), TET2 (n = 2; 4%), WT1 (n = 2; 4%)] pathways were recurrently mutated in TCs, but not in thymomas. Our results suggest a potential disruption of epigenetic homeostasis in TCs, and a substantial difference in genetic makeup between TCs and thymomas. Further investigation is warranted into the roles of epigenetic dysregulation in TC development and its potential for targeted therapy.
Full-text · Article · Dec 2014 · Scientific Reports
[Show abstract][Hide abstract] ABSTRACT: We analyzed 28 thymic epithelial tumors (TETs) using next-generation sequencing and identified a missense mutation (chromosome 7 c.74146970T>A) in GTF2I at high frequency in type A thymomas, a relatively indolent subtype. In a series of 274 TETs, we detected the GTF2I mutation in 82% of type A and 74% of type AB thymomas but rarely in the aggressive subtypes, where recurrent mutations of known cancer genes have been identified. Therefore, GTF2I mutation correlated with better survival. GTF2I β and δ isoforms were expressed in TETs, and both mutant isoforms were able to stimulate cell proliferation in vitro. Thymic carcinomas carried a higher number of mutations than thymomas (average of 43.5 and 18.4, respectively). Notably, we identified recurrent mutations of known cancer genes, including TP53, CYLD, CDKN2A, BAP1 and PBRM1, in thymic carcinomas. These findings will complement the diagnostic assessment of these tumors and also facilitate development of a molecular classification and assessment of prognosis and treatment strategies.
[Show abstract][Hide abstract] ABSTRACT: Recent investigations have made considerable progress in the understanding of tissue
regeneration driven by mesenchymal stromal cells (MSCs). Data indicate the anatomical
location of MSC as residing in the “perivascular” space of blood vessels dispersed
across the whole body. This histological localization suggests that MSCs contribute to
the formation of new blood vessels in vivo. Indeed, MSCs can release angiogenic factors
and protease to facilitate blood vessel formation and in vitro are able to promote/support
angiogenesis. However, the direct differentiation of MCSs into endothelial cells is still
matter of debate. Most of the conflicting data might arise from the presence of multiple
subtypes of cells with heterogeneous morpho functional features within the MSC
cultures. According to this scenario, we hypothesize that the presence of the recently
described Mesodermal Progenitor Cells (MPCs) within the MSCs cultures is responsible
for their variable angiogenic potential. Indeed, MPCs are Nestin-positive CD31-positive
cells exhibiting angiogenic potential that differentiate in MSC upon proper stimuli. The ISCT
criteria do not account for the presence of MPC within MSC culture generating confusion
in the interpretation of MSC angiogenic potential. In conclusion, the discover y of MPC
gives new insight in defining MSC ancestors in human bone marrow, and indicates the
tunica intima as a further, and previously overlooked, possible additional source of MSC.
Full-text · Article · May 2014 · Frontiers in Cell and Developmental Biology
[Show abstract][Hide abstract] ABSTRACT: In non-small-cell lung cancer, the molecular diagnosis of somatic mutations is instrumental for the choice of the most appropriate treatment. However, despite an initial response, resistance to tyrosine kinase inhibitors occurs and thereafter tumors progress. For this reason, next generation inhibitors able to overcome acquired resistances are currently in development. Therefore, the identification of the molecular determinants of resistance is needed to adapt treatment accordingly. The analysis of circulating cell-free tumor DNA represents a powerful tool to monitor the somatic changes induced by treatment. This review focuses on the most recent advantages in the diagnosis of acquired resistance in circulating cell-free tumor DNA and underlines the strategies ready to be translated in the clinical practice.
No preview · Article · Apr 2014 · Expert Review of Molecular Diagnostics
[Show abstract][Hide abstract] ABSTRACT: Molecular pathology of thymomas is poorly understood. Genomic aberrations are frequently identified in tumors but no extensive sequencing has been reported in thymomas. Here we present the first comprehensive view of a B3 thymoma at whole genome and transcriptome levels. A 55-year-old Caucasian female underwent complete resection of a stage IVA B3 thymoma. RNA and DNA were extracted from a snap frozen tumor sample with a fraction of cancer cells over 80%. We performed array comparative genomic hybridization using Agilent platform, transcriptome sequencing using HiSeq 2000 (Illumina) and whole genome sequencing using Complete Genomics Inc platform. Whole genome sequencing determined, in tumor and normal, the sequence of both alleles in more than 95% of the reference genome (NCBI Build 37). Copy number (CN) aberrations were comparable with those previously described for B3 thymomas, with CN gain of chromosome 1q, 5, 7 and X and CN loss of 3p, 6, 11q42.2-qter and q13. One translocation t(11;X) was identified by whole genome sequencing and confirmed by PCR and Sanger sequencing. Ten single nucleotide variations (SNVs) and 2 insertion/deletions (INDELs) were identified; these mutations resulted in non-synonymous amino acid changes or affected splicing sites. The lack of common cancer-associated mutations in this patient suggests that thymomas may evolve through mechanisms distinctive from other tumor types, and supports the rationale for additional high-throughput sequencing screens to better understand the somatic genetic architecture of thymoma.
[Show abstract][Hide abstract] ABSTRACT: Purposes:
To determine whether the deregulation of genes relevant for normal thymus development can contribute to the biology of thymic epithelial tumors (TET).
Using array comparative genomic hybridization, we evaluated the copy number aberrations of genes regulating thymus development. The expression of genes most commonly involved in copy number aberrations was evaluated by immunohistochemistry and correlated with patients' outcome. Correlation between FOXC1 copy number loss and gene expression was determined in a confirmation cohort. Cell lines were used to test the role of FOXC1 in tumors.
Among 31 thymus development-related genes, PBX1 copy number gain and FOXC1 copy number loss were presented in 43.0% and 39.5% of the tumors, respectively. Immunohistochemistry on a series of 132 TETs, including those evaluated by comparative genomic hybridization, revealed a correlation between protein expression and copy number status only for FOXC1 but not for PBX1. Patients with FOXC1-negative tumors had a shorter time to progression and a trend for a shorter disease-related survival. The correlation between FOXC1 copy number loss and mRNA expression was confirmed in a separate cohort of 27 TETs. Ectopic FOXC1 expression attenuated anchorage-independent cell growth and cell migration in vitro.
Our data support a tumor suppressor role of FOXC1 in TETs.
Preview · Article · Feb 2013 · Clinical Cancer Research
[Show abstract][Hide abstract] ABSTRACT: Background:
The WHO-classification was shown to be an independent prognostic marker in some but not all retrospective studies possibly due to lack of reproducibility. We investigated the reproducibility of the WHO-classification and its prognostic implication using a large series of resected thymomas.
Four independent pathologists histologically classified a surgical series of 129 thymic tumors in a blinded fashion. Fleiss' kappa-coefficient was used to assess the pathologists' overall agreement, and Cohen-Kappa to assess the agreement between two observers. Disease-related-survival (DRS) and progression-free-survival (PFS) curves were generated by Kaplan-Meier method and compared by log-rank test.
In 63/129 (48.8%) cases there was a complete agreement; in 43/129 (33.3%) cases 3/4 pathological diagnoses were identical; in 15/129 (11.6%) cases the diagnoses were identical by pair; in 8/129 (6.2%) cases three different pathological diagnoses were on record. The Kappa-correlation coefficient was only moderate (0.53). A following web review carried out on the 23 cases with at least two different diagnoses reached a complete consensus. The histotype showed a statistically significant impact on PFS and DRS in the classification provided by only two pathologists.
In this study, the agreement on WHO classification of thymomas was only moderate and this impacted on patients management. Web consensus conference on the diagnosis, more stringent diagnostic criteria or the adoption of referral diagnostic centres may substantially reduce discrepancies.
No preview · Article · Dec 2012 · Lung cancer (Amsterdam, Netherlands)
[Show abstract][Hide abstract] ABSTRACT: Arsenic Trioxide (ATO) is effective in about 20% of patients with myelodysplasia (MDS); its mechanisms of action have already been evaluated in vitro, but the in vivo activity is still not fully understood. Since ATO induces apoptosis in in vitro models, we compared the expression of 93 apoptotic genes in patients' bone marrow before and after ATO treatment. For this analysis, we selected 12 patients affected by MDS who received ATO in combination with Ascorbic Acid in the context of the Italian clinical trial NCT00803530, EudracT Number 2005-001321-28.
Real-time PCR quantitative assays for genes involved in apoptosis were performed using TaqMan® Assays in 384-Well Microfluidic Cards "TaqMan® Human Apoptosis Array".Quantitative RT-PCR for expression of EVI1 and WT1 genes was also performed. Gene expression values (Ct) were normalized to the median expression of 3 housekeeping genes present in the card (18S, ACTB and GAPDH).
ATO treatment induced up-regulation of some pro-apoptotic genes, such as HRK, BAK1, CASPASE-5, BAD, TNFRSF1A, and BCL2L14 and down-regulation of ICEBERG. In the majority of cases with stable disease, apoptotic gene expression profile did not change, whereas in cases with advanced MDS more frequently pro-apoptotic genes were up-regulated. Two patients achieved a major response: in the patient with refractory anemia the treatment down-regulated 69% of the pro-apoptotic genes, whereas 91% of the pro-apoptotic genes were up-regulated in the patient affected by refractory anemia with excess of blasts-1. Responsive patients showed a higher induction of BAD than those with stable disease. Finally, WT1 gene expression was down-regulated by the treatment in responsive cases.
These results represent the basis for a possible association of ATO with other biological compounds able to modify the apoptotic pathways, such as inhibitors of the BCL2 family.
[Show abstract][Hide abstract] ABSTRACT: The molecular pathology of thymic epithelial tumors (TETs) is largely unknown. Using array comparative genomic hybridization (CGH), we evaluated 59 TETs and identified recurrent patterns of copy number (CN) aberrations in different histotypes. GISTIC algorithm revealed the presence of 126 significant peaks of CN aberration, which included 13 cancer-related genes. Among these peaks, CN gain of BCL2 and CN loss of CDKN2A/B were the only genes in the respective regions of CN aberration and were associated with poor outcome. TET cell lines were sensitive to siRNA knockdown of the anti-apoptotic molecules BCL2 and MCL1. Gx15-070, a pan-BCL2 inhibitor, induced autophagy-dependent necroptosis in TET cells via a mechanism involving mTOR pathways, and inhibited TET xenograft growth. ABT263, an inhibitor of BCL2/BCL-XL/BCL-W, reduced proliferation in TET cells when administered in combination with sorafenib, a tyrosine kinase inhibitor able to downregulate MCL1. Immunohistochemistry on 132 TETs demonstrated that CN loss of CDKN2A correlated with lack of expression of its related protein p16(INK4) and identified tumors with poor prognosis. The molecular markers BCL2 and CDKN2A may be of potential value in diagnosis and prognosis of TETs. Our study provides the first preclinical evidence that deregulated anti-apoptotic BCL2 family proteins may represent suitable targets for TET treatment.
[Show abstract][Hide abstract] ABSTRACT: Sorafenib improves overall survival and time to progression of advanced hepatocellular (aHCC) patients such as demonstrated in 2 phase III trials. However, aHCC patients' outcome is still poor despite these results. In order to improve the efficacy of systemic treatment for aHCC, we evaluated the combination of sorafenib plus 5-fluorouacil infusion in a phase II trial.
Patients with aHCC not eligible for loco-regional therapies, Child-Pugh A-B, ECOG-PS 0-1, and without history of anti-cancer systemic treatment were enrolled. Treatment schedule was: sorafenib 400 mg/bid continuously and continuum infusion of 5-fluorouracil 200 mg/sqm/daily day 1-14 every 3 weeks.
Thirty-nine patients were enrolled: ECOG-PS 0-1: 29-10, Child-Pugh A-B: 36-3. Grade 3/4 (%) toxicities included: diarrhea 5.1/0, mucositis 20.5/2.6, hand foot skin reaction 20.5/0, skin rash 10.5/0, hypertension 10.3/0, hyperbilirubinemia 5.1/2.6, glutamic-oxaloacetic transaminase increase 10.3/0, glutamic-pyruvic transaminase increase 7.7/0, cardiac toxicity (one heart failure, two atrial fibrillation cases) 7.7/0, and bleeding (melena) in 2.6/0. One partial response was observed. Stable disease was obtained in 46.2% of patients with a median duration of 16.2 months. Median time to progression was 8 months (CI 95% = 5.7-10.4), and median overall survival was 13.7 months (CI 95% = 9.5-17.9).
The results show an encouraging disease control rate, time to progression, and overall survival. The combination of sorafenib and 5-fluorouracil was feasible, and the side effects were manageable for patients carefully selected for liver function and performance status.
No preview · Article · Mar 2012 · Cancer Chemotherapy and Pharmacology
[Show abstract][Hide abstract] ABSTRACT: Pancreatic cancer is the fourth leading cause of cancer-related death, and studies on the clinical relevance of its genomic imbalances are warranted.
Recurrent copy number alterations of cytobands and genes were analyzed by array comparative genomic hybridization (aCGH) in 44 resected pancreatic cancer specimens. Prognostic markers identified by aCGH were validated by PCR gene copy number assay in an independent validation cohort of 61 resected pancreatic cancers. The functions of gene identified were evaluated by proliferation, cell cycle, and migration assays in pancreatic cancer cells.
We showed recurrent copy number gains and losses in the first cohort. Loss of 18q22.3 was significantly associated with short-term overall survival in the first cohort (P = 0.019). This cytoband includes the carboxypeptidase of glutamate-like (CPGL) gene. CPGL gene deletion was associated with shorter overall survival in the validation cohort (P = 0.003). CPGL deletion and mutations of TP53 or Kras seem to be independent events. A Cox model analysis of the two cohorts combined showed that loss of 18q22.3/deletion of the CPGL gene was an independent poor prognostic factor for overall survival (HR = 2.72, P = 0.0007). Reconstitution of CPGL or its splicing variant CPGL-B into CPGL-negative pancreatic cancer cells attenuated cell growth, migration, and induced G(1) accumulation.
Loss of 18q22.3/deletion of the CPGL gene is a poor prognostic marker in resected pancreatic cancer, and functional studies suggest the CPGL gene as growth suppressor gene in pancreatic cancer.
Full-text · Article · Nov 2011 · Clinical Cancer Research
[Show abstract][Hide abstract] ABSTRACT: A key challenge in the treatment of thymoma and thymic carcinoma (TC) is in improving our understanding of the molecular biology of these relatively rare tumors. In recent years, significant efforts have been made to dissect the molecular pathways involved in their carcinogenesis. Here we discuss the results of large-scale genomic analyses conducted to date and review the most active chemotherapies and targeted treatments.
We reviewed the literature for chemotherapeutic trials in the last 20 years and trials involving targeted therapies between 1999 and 2010. The search was supplemented by a review of abstracts presented at the annual meetings of the American Society of Clinical Oncology (from 1999 to 2010), at the first International Conference on Thymic Malignancies in 2009, and at a follow-up meeting of the newly formed International Thymic Malignancies Interest Group in 2010.
Surgery remains the treatment of choice for operable tumors, whereas chemotherapy is standard in locally advanced and metastatic disease. Thus far, targeted therapies have been developed empirically. Histone deacetylase inhibitors have shown some activity in thymoma whereas sunitinib may be active in TC. There are no data to support the use of HER2- or EGFR-targeted therapies in thymic malignancies.
Drug development for the treatment of thymic malignancies is difficult because of the rarity of these tumors. Ethnic differences are becoming apparent, with aggressive subtypes being observed in Asians and African Americans. Incremental improvements in our understanding of tumor biology suggest that molecular profiling-directed therapies may be the preferred route of investigation in the future.
No preview · Article · Nov 2011 · Journal of Clinical Oncology
[Show abstract][Hide abstract] ABSTRACT: Melanoma is an immunogenic tumour but, despite the wide range of immunotherapies tested, only few promising results have been reported to date. Both in vitro and in xenograft models, γδ lymphocyte-mediated cytotoxicity against melanoma cells has been reported. IL-2/zoledronate treatment can expand γδ cells in vitro and in animal models. This could represent an immunotherapeutic strategy against melanoma. To evaluate the feasibility of this approach, we studied γδ lymphocyte phenotype from patients with melanoma, their ability to be expanded by IL-2/zoledronate and their cytotoxic activity against SK-MEL-30 cell line.
Peripheral blood samples were collected from 30 patients with melanoma and 10 healthy donors. Percentage of γδ lymphocytes and CD45RO+CD27+, CD45RA+CD27-, CD57+, Vγ9Vδ2 subpopulations were evaluated by flow cytometry. IL-2/zoledronate γδ cell expansion rate and their cytotoxicity against SK-MEL-30 cell line were studied.
A percentage decrease in circulating Vγ9Vδ2 and an increase in CD45RA+CD27- and CD57+ γδ lymphocytes were observed in melanoma. IL-2/zoledronate expansion rate did not differ between controls and patients with melanoma but cytotoxicity against SK-MEL-30 appeared reduced.
Our results show that γδ cell function is impaired in patients with advanced melanoma and suggest a possible role in tumour progression.
Full-text · Article · Nov 2011 · European Journal of Clinical Investigation