Marta Lorenzo

Molecular alterations of EGFR and PTEN in prostate cancer: association with high-grade and advanced-stage carcinomas

Prostate cancer is the second cause of cancer-related death in men of the Western world. The potential prognostic role of the combined alterations in EGFR and PTEN in prostate cancer is not well established. It was the aim of the study to investigate this role. Prevalence of EGFR and PTEN somatic mutations, EGFR amplification and EGFR protein expression were investigated in a series of prostate adenocarcinomas, classified according to the current Gleason grading system. Mutational analysis revealed eight EGFR and three PTEN mutations in 98 (8%) and 92 (3%) prostate adenocarcinomas, respectively. The combined prevalence of EGFR–PTEN mutations was 11%. EGFR overexpression was present in 31% of adenocarcinomas, with a marginally significant difference (P=0.068) between Gleason grade ≤7 adenocarcinomas and Gleason grade ≥8 and metastatic adenocarcinomas. Four cases (4 of 31; 13%) had an EGFR gene gain due to chromosome 7 polysomy. In 35% of adenocarcinomas we found some type of EGFR–PTEN alteration, with a tendency to be associated with advanced-stage prostate adenocarcinomas (P=0.04). The IVS18+19 polymorphism was also associated with more advanced prostate adenocarcinomas. This is the first study reporting mutations of EGFR and PTEN in the same series of prostate adenocarcinomas. Protein overexpression is the most frequent EGFR abnormality. Mutations in EGFR and PTEN genes are a minor event, although prostate cancer represents the third neoplasm in which the EGFR gene mutations are more prevalent. Alterations in the EGFR–PTEN signaling pathway are present in a third of prostate adenocarcinomas, particularly affecting the more advanced cases.

Mutations in FGFR3 and PIK3CA, singly or combined with RAS and AKT1, are associated with AKT but not with MAPK pathway activation in urothelial bladder cancer ☆

Different members of the phosphoinositide 3 kinase--serine threonine protein kinase (PI3K-AKT) pathway are altered in bladder cancer. Fibroblast growth factor receptor 3 (FGFR3) mutations characterize the low-grade tumors, and RAS genes are mutated in approximately 13% of all bladder tumors. Interestingly, a percentage of bladder tumors have alterations in more than 1 PI3K-AKT or rat sarcoma viral oncogene homolog-RAF mitogen activated protein kinase (RAS-MAPK) pathway gene or their upstream regulators, but some combinations are mutually exclusive. We analyzed mutations in FGFR3, phosphoinositide 3 kinase catalytic alpha polypeptide (PIK3CA), v-akt murine thymoma viral oncogene homolog 1 (AKT1), v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (KRAS), v-Ha-ras Harvey rat sarcoma viral oncogene homolog (HRAS), and v-raf murine sarcoma viral oncogene homolog B1 (BRAF) in 88 urothelial cell carcinomas and the immunohistochemical expression of phospho-v-akt murine thymoma viral oncogene homolog (AKT) and mitogen-activated protein kinase 1 and 2 (pERK1/2) in 80 and 77 urothelial cell carcinomas, respectively. Approximately 43% and 20.5% of tumors presented 1 and 2 mutated genes, respectively. FGFR3 mutations were more frequent alone, whereas PIK3CA mutations were associated with another mutated gene (FGFR3 and KRAS). Overall, mutated FGFR3 (FGFR3(mut)) and mutated FGFR3 (FGFR3(mut))-mutated PIK3CA (PIK3CA(mut)) genotypes were associated with low-grade bladder tumors and mutated PIK3CA (PIK3CA(mut))-mutated KRAS (KRAS(mut)) and mutated AKT1 (AKT1(mut)) were only present in high-grade tumors. There are no mutated FGFR3 (FGFR3(mut))-mutated RAS (RAS(mut)) nor mutated PIK3CA (PIK3CA(mut))-mutated AKT1 (AKT1(mut)) combinations. Fifty percent and 56% of tumors showed high levels of pAKT and pERK1/2, respectively. High levels of pAKT were associated with total mutations, FGFR3(mut), and PIK3CA(mut) tumors but not with tumor grade or stage. Wild-type tumors presented significantly higher pERK1/2 expression. Mutations in FGFR3 and FGFR3-PIK3CA but not single PIK3CA mutations characterize low-grade bladder tumors. Single FGFR3 or PIK3CA mutations and the different mutation combinations FGFR3-PIK3CA/AKT1 and PIK3CA-RAS can activate the AKT but not the MAPK pathway. Other genes different from FGFR3 may be related with the pERK activation in bladder tumors.

PI3K signaling pathway is activated by PIK3CA mRNA overexpression and copy gain in prostate tumors, but PIK3CA , BRAF , KRAS and AKT1 mutations are infrequent events

The phosphatidylinositol 3-kinase (PI3K)–AKT and RAS–MAPK pathways are deregulated in a wide range of human cancers by gain or loss of function in several of their components. Our purpose has been to identify genetic alterations in members of these pathways in prostate cancer. A total of 102 prostate tumors, 79 from prostate cancer alone (group G1) and 23 from bladder and prostate cancer patients (G2), are the subject of this study. In 20 of these 23, the bladder tumors were also analyzed. PIK3CA, KRAS, BRAF and AKT1 mutations were analyzed by direct sequencing, and BRAF also by pyrosequencing. PIK3CA quantitative mRNA expression and fluorescence in situ hybridization (FISH) gains were tested in 25 and 32 prostate tumors from both groups (G1 and G2), respectively. Immunohistochemistry for pAKT was performed in 55 prostate tumors. Of 25 prostate tumors, 10 (40%) had PIK3CA mRNA overexpression that was statistically associated with Gleason score ≥7 (P=0.018). PIK3CA copy gain was detected in 9 of 32 (28%) prostate tumors. Of 20 bladder tumors, 3 (15%) displayed mutations in PIK3CA, KRAS and AKT1, the corresponding prostate tumors being wt. We also detected a previously not reported PIK3CA polymorphism (IVS9+91) in two prostate tumors. In all, 56% of prostate tumors overexpressed pAKT. There is a statistical association (P<0.0001) of strong pAKT immunostaining with high Gleason score, and with PIK3CA alterations (mRNA overexpression and/or FISH gains). PIK3CA gene is deregulated by mRNA overexpression and DNA gain in ∼40 and 28% of prostate tumors, respectively. High-grade prostate tumors are associated with PIK3CA mRNA overexpression, but not with FISH status. PIK3CA, BRAF, KRAS and AKT1 mutations are very infrequent events in prostate tumors. However, PI3K signaling pathway is activated by PIK3CA FISH gain and/or mRNA overexpression, leading to an increased pAKT protein expression.

Association of ERG and TMPRSS2‐ERG with grade, stage, and prognosis of prostate cancer is dependent on their expression levels

There is controversy in the literature on the role of the fusion TMPRSS2‐ERG in the pathogenesis and progression of prostate cancer. The quantitative differences in TMPRSS2‐ERG fusion expression have received very limited attention in the literature.

A 12-Gene Expression Signature Is Associated with Aggressive Histological in Prostate Cancer: SEC14L1 and TCEB1 Genes Are Potential Markers of Progression

The main challenge for clinical management of prostate cancer is to distinguish tumors that will progress faster and will show a higher tendency to recur from the more indolent ones. We have compared expression profiles of 18 prostate cancer samples (seven with a Gleason score of 6, eight with a Gleason score of 7, and three with a Gleason score of ≥8) and five nonneoplastic prostate samples, using the Affymetrix Human Array GeneChip Exon 1.0 ST. Microarray analysis revealed 99 genes showing statistically significant differences among tumors with Gleason scores of 6, 7, and ≥8. In addition, mRNA expression of 29 selected genes was analyzed by real-time quantitative RT-PCR with microfluidic cards in an extended series of 30 prostate tumors. Of the 29 genes, 18 (62%) were independently confirmed in the extended series by quantitative RT-PCR: 14 were up-regulated and 4 were down-regulated in tumors with a higher Gleason score. Twelve of these genes were differentially expressed in tumors with a Gleason score of 6 to 7 versus ≥8. Finally, IHC validation of the protein levels of two genes from the 12-gene signature (SEC14L1 and TCEB1) showed strong protein expression levels of both genes, which were statistically associated with a high combined Gleason score, advanced stage, and prostate-specific antigen progression. This set of genes may contribute to a better understanding of the molecular basis of prostate cancer. TCEB1 and SELC14L1 are good candidate markers for predicting prognosis and progression of prostate cancer.

Heterogeneity of Tumor and Immune Cell PD-L1 Expression and Lymphocyte Counts in Surgical NSCLC Samples

Background Immune‐checkpoint inhibitors against programmed cell death protein 1 (PD‐1)/programmed death‐ligand 1 (PD‐L1) have shown remarkable therapeutic activity in non–small‐cell lung cancer (NSCLC). However, biomarker‐based patient selection remains a challenge. Our aim was to assess the heterogeneity of various immune markers between different tumor areas of surgically resected NSCLC specimens. Materials and Methods We included 94 adenocarcinoma (ADC) and 50 squamous cell carcinoma (SCC) specimens. Two distinct tumor areas of each tumor sample were selected and incorporated into tissue microarrays. PD‐L1 expression in tumor cells (TCs) and immune cells (ICs) was assessed using clone SP142 (Ventana). PDL1 gene amplification was assessed using fluorescence in situ hybridization. CD3 and CD8 densities were quantified using digital image‐based analysis. Heterogeneity was assessed using kappa agreement index (KI) and intraclass correlation coefficient. Results Prevalence of PD‐L1 expression was 16.8% in TCs and 27.8% in ICs. Eleven tumors (7.6%) showed PDL1 amplification. In ADC, KI of PD‐L1 TC and IC expression between cores was 0.465 and 0.260, compared with 0.274 and 0.124 in SCC, respectively. Higher concordance was observed for PDL1 amplification (KI, 0.647 in ADC and KI, 1 in SCC). Eleven (61.1%) of 18 amplified cores showed PD‐L1 staining in < 5% of TCs. Intraclass correlation coefficients for CD3 and CD8 were 0.293 and 0.186 in ADC and 0.489 and 0.610 in SCC samples, respectively. Conclusions We found significant heterogeneity of PD‐L1 expression in both ADC and SCC samples, especially in the IC compartment. Heterogeneous expression of PD‐L1 could misclassify patients for PD‐1/PD‐L1‐directed therapies. Micro‐Abstract Expression of programmed death‐ligand 1 (PD‐L1) in tumor cells and infiltrating immune cells was retrospectively analyzed in a cohort of surgically‐treated patients with non–small‐cell lung cancer. There was significant discordance of PD‐L1 expression between different tumor areas, especially in the immune cell compartment. Heterogeneous PD‐L1 expression represents a challenge for adequate biomarker‐based selection of patients for programmed cell death protein 1/PD‐L1‐directed therapies.

CXCR4 mRNA overexpression in high grade prostate tumors: Lack of association with TMPRSS2-ERG rearrangement

The TMPRSS2-ERG fusion has been reported in 42 to 78% of prostate tumors. More than 90% of ERG-overexpressing tumors harbor the fusion. The relationship between the TMPRSS2-ERG fusion and prognosis is controversial. Different studies have suggested an association between CXCR4 and ERG overexpression resulting from the TMPRSS2-ERG rearrangement. The aim of this study was to investigate the relationship between CXCR4 expression, TMPRSS2-ERG fusion and Gleason grade in prostate cancer. TMPRSS2-ERG rearrangement was investigated by FISH (n=44), ERG protein by IHC (n=84), and CXCR4 by quantitative RT-PCR (n=44). TMPRSS2-ERG rearrangement and ERG protein expression were present in almost 50% of the cases, without statistical differences between the different Gleason score groups. There was a very high concordance between FISH and IHC techniques (Kappa Index=0.954). Seventy percent of Gleason ⩾ 8 prostate tumors overexpressed CXCR4 mRNA, and the difference in CXCR4 expression with Gleason < 8 cases was statistically significant (p=0.009). There was no association between ERG protein and CXCR4 mRNA expression. In conclusion, our results reveal for the first time that CXCR4 overexpression is associated with high Gleason score prostate tumors, but that it is independent of the TMPRSS2-ERG rearrangement.

CD274 (PDL1) and JAK2 genomic amplifications in pulmonary squamous-cell and adenocarcinoma patients

CD274 (PDL1) and JAK2 (9p24.1) gene amplifications have been recently described in pulmonary carcinomas in association with programmed death‐ligand 1 (PD‐L1) expression. Furthermore, PTEN loss has been explored preclinically in relation to PD‐L1 expression. Our aim was to determine whether these genomic alterations affect PD‐L1 expression levels in non‐small‐cell lung cancer.

Concurrent TMPRSS2‐ERG and SLC45A3‐ERG rearrangements plus PTEN loss are not found in low grade prostate cancer and define an aggressive tumor subset

SLC45A3 is the second most common ERG partner in prostate cancer (PrCa). Coexisting TMPRSS2 and SLC45A3 rearrangements are found in a subset of cases, but the meaning is still unknown.

FOXO1 down-regulation is associated with worse outcome in bladder cancer and adds significant prognostic information to p53 overexpression

Nuclear FOXOs mediate cell cycle arrest and promote apoptosis. FOXOs and p53 could have similar effects as tumor suppressor genes. In spite of extensive literature, little is known about the role of FOXO1 and its relationship with p53 status in bladder cancer. Expression of FOXO1 and p53 were analyzed by immunohistochemistry in 162 urothelial carcinomas (UC). Decreased FOXO1 expression, p53 overexpression and the combination FOXO1 down-regulation/p53 overexpression were strongly associated with high grade (P=.030; P=.017; P=.004, respectively), high stage (P=.0001; P<.0001; P<.0001, respectively) or both (P=.0004; P<.0001; P<.0001, respectively). In the overall series of cases, p53 overexpression was associated with tumor progression (hazard ratio [HR]=3.18, 95% confidence interval [CI] 1.19-8.48, P=.02), but this association was even stronger if having any alteration in any of the 2 genes was considered (HR=3.51, 95% CI 1.34-9.21, P=.01). Having both FOXO1 down-regulation and p53 overexpression was associated with disease recurrence (HR=2.75, 95% CI 1.06-7.13, P=.03). In the analysis of the different subgroups, having any alteration in any of the 2 genes was associated with progression in low-grade (P=.005) and pTa (P=.006) tumors. Finally, the combined FOXO1 down-regulation/p53 overexpression was associated with disease recurrence specifically in high-grade (P=.04) and in pT1 stage tumors (P=.007). Adding FOXO1 expression to the immunohistochemical analysis of p53 can provide relevant prognostic information on progression and recurrence of bladder cancer. It may be particularly informative on the risk of progression in the more indolent and on the risk of recurrence in the more aggressive tumors.