FGFR4 Arg388 allele correlates with tumour thickness and FGFR4 protein expression with survival of melanoma patients

FGFR4 Arg388 genotype is associated with pathological complete response to neoadjuvant chemotherapy for primary breast cancer

BACKGROUND

A single-nucleotide polymorphism (SNP) in the FGFR4 gene is associated with poor prognosis in solid tumors. A recent study presented the first evidence that FGFR4 Arg388 could predict resistance to adjuvant chemotherapy in breast cancer. The present study evaluates the potential of this SNP to predict response to neoadjuvant chemotherapy (NCT) for primary breast cancer (PBC).

METHODS

As part of a randomized phase II trial, 257 patients received either doxorubicin-cyclophosphamide (AC) or doxorubicin-pemetrexed (AP) followed by docetaxel (Doc; Taxotere) as NCT for T2-4/N0-2/M0 PBC. FGFR4 genotype analyzed on germline DNA was correlated with clinicopathologic variables, clinical response, and pathological complete response (pCR) using univariate and multivariate analyses.

RESULTS

Only axillary lymph node status was associated with FGFR4 Arg388 [odds ratio (OR) 1.82, P = 0.03]. Joint analysis of both treatment arms revealed a correlation of FGFR4 Arg388 with clinical response (OR 2.14, P = 0.03) but not with pCR. In the AC-Doc arm, however, FGFR4 Arg388 was a strong predictor of pCR in the multivariate analysis (OR 3.79, P = 0.03). A significant interaction between FGFR4 genotype and treatment (P = 0.01) was found, indicating a therapy-specific effect.

CONCLUSION

We provide the evidence that FGFR4 388Arg is an independent predictor of pCR following AC-Doc as NCT in PBC.

A single nucleotide change in the mouse genome accelerates breast cancer progression

In the growth factor receptor gene FGFR4 the presence of the common single nucleotide polymorphism Arg388 has been associated with progression of various types of cancer including breast cancer. However, a causative relationship is not readily assigned due to genetic heterogeneity in different patient cohorts. To address this issue, we compared the effects of this allele on malignant progression in the WAP-TGFalpha transgenic mouse model of breast cancer. A knock-in strain was generated to introduce an analogous Arg385 allele into the murine FGFR4 gene. Mouse embryonic fibroblasts derived from this strain displayed accelerated cell transformation, with transformed cells exhibiting greater motility and invasive behavior. In the in vivo context of TGFalpha-induced mammary carcinogenesis, tumor development and progression was significantly advanced in tumor mass, size, and onset of pulmonary metastases. Our findings definitively identify the FGFR4 Arg388 allele as a functional prognostic marker for breast cancer progression.

The FGFR4 Y367C mutant is a dominant oncogene in MDA-MB453 breast cancer cells

Mutational analysis of oncogenes is critical for our understanding of cancer development. Oncogenome screening has identified a fibroblast growth factor receptor 4 (FGFR4) Y367C mutation in the human breast cancer cell line MDA-MB453. Here, we investigate the consequence of this missense mutation in cancer cells. We show that MDA-MB453 cells harbouring the mutation are insensitive to FGFR4-specific ligand stimulation or inhibition with an antagonistic antibody. Furthermore, the FGFR4 mutant elicits constitutive phosphorylation leading to an activation of the mitogen-activated protein kinase cascade as shown by an enhanced Erk1/2 phosphorylation. Cloning and ectopic expression of the FGFR4 Y367C mutant in HEK293 cells revealed high pErk levels and enhanced cell proliferation. Based on these findings, we propose that FGFR4 may be a driver of tumour growth, particularly when highly expressed or stabilized and constitutively activated through genetic alterations. As such, FGFR4 presents an option for further mutational screening in tumours and is an attractive cancer target with the therapeutic potential.

Genetic variants in FGFR2 and FGFR4 genes and skin cancer risk in the Nurses' Health Study

Background

The human fibroblast growth factor (FGF) and its receptor (FGFR) play an important role in tumorigenesis. Deregulation of the FGFR2 gene has been identified in a number of cancer sites. Overexpression of the FGFR4 protein has been linked to cutaneous melanoma progression. Previous studies reported associations between genetic variants in the FGFR2 and FGFR4 genes and development of various cancers.

Methods

We evaluated the associations of four genetic variants in the FGFR2 gene highly related to breast cancer risk and the three common tag-SNPs in the FGFR4 gene with skin cancer risk in a nested case-control study of Caucasians within the Nurses' Health Study (NHS) among 218 melanoma cases, 285 squamous cell carcinoma (SCC) cases, 300 basal cell carcinoma (BCC) cases, and 870 controls.

Results

We found no evidence for associations between these seven genetic variants and the risks of melanoma and nonmelanocytic skin cancer.

Conclusion

Given the power of this study, we did not detect any contribution of genetic variants in the FGFR2 or FGFR4 genes to inherited predisposition to skin cancer among Caucasian women.

Tissue biomarkers for prognosis in cutaneous melanoma: a systematic review and meta-analysis

In the clinical management of early-stage cutaneous melanoma, it is critical to determine which patients are cured by surgery alone and which should be treated with adjuvant therapy. To assist in this decision, many groups have made an effort to use molecular information. However, although there are hundreds of studies that have sought to assess the potential prognostic value of molecular markers in predicting the course of cutaneous melanoma, at this time, no molecular method to improve risk stratification is part of recommended clinical practice. To help understand this disconnect, we conducted a systematic review and meta-analysis of the published literature that reported immunohistochemistry-based protein biomarkers of melanoma outcome. Three parallel search strategies were applied to the PubMed database through January 15, 2008, to identify cohort studies that reported associations between immunohistochemical expression and survival outcomes in melanoma that conformed to the REMARK criteria. Of the 102 cohort studies, we identified only 37 manuscripts, collectively describing 87 assays on 62 distinct proteins, which met all inclusion criteria. Promising markers that emerged included melanoma cell adhesion molecule (MCAM)/MUC18 (all-cause mortality [ACM] hazard ratio [HR] = 16.34; 95% confidence interval [CI] = 3.80 to 70.28), matrix metalloproteinase-2 (melanoma-specific mortality [MSM] HR = 2.6; 95% CI = 1.32 to 5.07), Ki-67 (combined ACM HR = 2.66; 95% CI = 1.41 to 5.01), proliferating cell nuclear antigen (ACM HR = 2.27; 95% CI = 1.56 to 3.31), and p16/INK4A (ACM HR = 0.29; 95% CI = 0.10 to 0.83, MSM HR = 0.4; 95% CI = 0.24 to 0.67). We further noted incomplete adherence to the REMARK guidelines: 14 of 27 cohort studies that failed to adequately report their methods and nine studies that failed to either perform multivariable analyses or report their risk estimates were published since 2005.

Melanoma biomarkers: current status and vision for the future

Melanoma is the leading cause of death from skin cancer in industrialized countries. Clinical and histological variables such as primary tumor invasion, ulceration, and lymph node status might fail to identify early-stage disease that will eventually progress. Tumor biomarkers might help to identify patients with early-stage melanoma who are likely to develop advanced disease and would benefit from additional therapies. These biomarkers offer the possibility of improved tumor staging through the molecular detection of microscopic lymph node metastases that are not visible on routine histological examination. We focus on biomarkers localized to the tumor tissue and those of prognostic value. We give an overview of the melanoma biomarkers that are most helpful for prediction of patients' outcomes, and discuss the primary melanoma biomarkers that have been shown to be of prognostic significance independent of primary tumor thickness and other common clinical prognostic indicators. Although such tumor-associated biomarkers are thought to have the greatest potential, a lack of reliable data makes their true clinical utility difficult to determine. We conclude that several biomarkers show promise in early studies; however, additional large-scale studies are warranted. We suggest cautious optimism for the field of melanoma biomarkers, which we expect to be translated into clinical practice over the next few years.

Polymorphisms of fibroblast growth factor receptor 4 have association with the development of prostate cancer and benign prostatic hyperplasia and the progression of prostate cancer in a Japanese population

Fibroblast growth factor receptor 4 (FGFR4) is a member of a family of transmembrane receptors with ligand-induced tyrosine kinase activity. The Glycine (Gly) to Arginine (Arg) polymorphism at codon 388 (Gly388Arg), which encodes an amino acid in the transmembrane part of the FGFR4 gene, was reported to be associated with an increased risk in some carcinomas. We investigated the association between the Gly388Arg polymorphism or the G or A polymorphism at intron 11 (rs2011077) of FGFR4, which was located 1,213 base pairs apart from the Gly388Arg polymorphism, and the risk of prostate cancer or benign prostate hyperplasia (BPH), and the prostate cancer disease status in Japanese men. Genotypes of Gly388Arg and rs2011077 polymorphisms of FGFR4 were determined in 492 patients with prostate cancer, 165 patients with BPH and 179 male controls. Regarding the Gly388Arg polymorphism, individuals with the ArgArg genotype had a 2.207- and 1.958-fold increased risk of prostate cancer and BPH, and a 1.804-fold increased risk of metastatic prostate cancer compared with those with the GlyGly genotype. Regarding the rs2011077 polymorphism, individuals with the GG genotype had a 6.260- and 3.033-fold increased risk of prostate cancer and BPH, and a 5.550-fold increased risk of metastatic prostate cancer compared with those with the AA genotype. Our results indicate that the FGFR4 Arg allele of the Gly388Arg polymorphism and the G allele of the rs2011077 polymorphism have a significant impact on the development of prostate cancer and BPH, and the progression of prostate cancer in a Japanese population.

Altered fibroblast growth factor receptor 4 stability promotes prostate cancer progression

Fibroblast growth factor receptor 4 (FGFR-4) is expressed at significant levels in almost all human prostate cancers, and expression of its ligands is ubiquitous. A common polymorphism of FGFR-4 in which arginine (Arg(388)) replaces glycine (Gly(388)) at amino acid 388 is associated with progression in human prostate cancer. We show that the FGFR-4 Arg(388) polymorphism, which is present in most prostate cancer patients, results in increased receptor stability and sustained receptor activation. In patients bearing the FGFR-4 Gly(388) variant, expression of Huntingtin-interacting protein 1 (HIP1), which occurs in more than half of human prostate cancers, also results in FGFR-4 stabilization. This is associated with enhanced proliferation and anchorage-independent growth in vitro. Our findings indicate that increased receptor stability and sustained FGFR-4 signaling occur in most human prostate cancers due to either the presence of a common genetic polymorphism or the expression of a protein that stabilizes FGFR-4. Both of these alterations are associated with clinical progression in patients with prostate cancer. Thus, FGFR-4 signaling and receptor turnover are important potential therapeutic targets in prostate cancer.

The RTK/RAS/BRAF/PI3K pathways in melanoma: biology, small molecule inhibitors, and potential applications

The discovery of mutations in the BRAF signaling molecule in a large proportion of cutaneous melanomas immediately suggested the prospect of effective therapies for this disease. The most appealing initial target has been BRAF itself, as most mutations involve a single residue in the kinase domain of the protein. But the identification of the high mutation rate in this signaling intermediate also suggests that other molecules up- and downstream of BRAF might be productively targeted. Indeed, several receptor tyrosine kinases, as well as RAS, are mutated in a small number of melanoma cases. Moreover, genetic alterations in the phosphotidylinositol-3-kinase (PI3K) pathway, especially in PTEN, suggest that this route also poses opportunities for therapeutic exploitation. We will review here the genetic evidence suggesting the utility of targets on these pathways. We will also summarize the recent clinical data that have accumulated from initial trials designed to test BRAF inhibition and targeting of other molecules. Finally, we provide an overview of molecules entering the clinic and soon to be tested in clinical studies, as well as strategies for their employment as monotherapy and in combinations.

Gene expression profiling in melanoma identifies novel downstream effectors of p14ARF

p14ARF is inactivated by deletions/mutations in many cancer types and can suppress cell growth by both p53-dependent and p53-independent mechanisms. To identify novel downstream effectors of p14ARF, we used gene expression profiling as a primary screening tool to select candidates for follow up validation studies using in vitro cell-based assays. Gene expression profiles of a panel of 35 melanoma cell lines with either wild-type (n = 12) or mutant (n = 23) p14ARF were compared to identify genes associated with inactivation of p14ARF. Analysis of the microarray data identified 1,316 probe sets that were significantly (p < 0.01) differentially expressed between the p14ARF wild-type and mutant cell lines. Pathway analysis of these genes showed an overrepresentation of many receptor-mediated signal transduction pathways, e.g. TGFbeta, EGF, HGF, PDGF, MAPK, Wnt and integrin pathways. A number of components of these pathways, including FLRT3, RUNX2, MIG-6 and SMURF2 were confirmed as downstream targets of p14ARF using p14ARF-inducible cell lines and RNAi. We propose that regulation of these genes may contribute to melanoma development when p14ARF function is lost.

Joint association of polymorphism of the FGFR4 gene and mutation TP53 gene with bladder cancer prognosis

The impact of the fibroblast growth factor receptor 4 (FGFR4) Gly388Arg polymorphism on bladder cancer is unknown. We found no clear correlations between the FGFR4 genotype and risk of bladder cancer or pathological parameters. Neither the polymorphism nor TP53 mutation status was an independent predictor of prognosis, but they might act jointly on the disease-specific survival of patients.