Basic fibroblast growth factor and angiogenesis in squamous carcinoma of the tongue

Role of Basic Fibroblast Growth Factor in Cancer: Biological Activity, Targeted Therapies, and Prognostic Value

Cancer is the leading cause of death worldwide; thus, it is necessary to find successful strategies. Several growth factors, such as vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF, FGF2), and transforming growth factor beta (TGF-β), are involved in the main processes that fuel tumor growth, i.e., cell proliferation, angiogenesis, and metastasis, by activating important signaling pathways, including PLC-γ/PI3/Ca2+ signaling, leading to PKC activation. Here, we focused on bFGF, which, when secreted by tumor cells, mediates several signal transductions and plays an influential role in tumor cells and in the development of chemoresistance. The biological mechanism of bFGF is shown by its interaction with its four receptor subtypes: fibroblast growth factor receptor (FGFR) 1, FGFR2, FGFR3, and FGFR4. The bFGF–FGFR interaction stimulates tumor cell proliferation and invasion, resulting in an upregulation of pro-inflammatory and anti-apoptotic tumor cell proteins. Considering the involvement of the bFGF/FGFR axis in oncogenesis, preclinical and clinical studies have been conducted to develop new therapeutic strategies, alone and/or in combination, aimed at intervening on the bFGF/FGFR axis. Therefore, this review aimed to comprehensively examine the biological mechanisms underlying bFGF in the tumor microenvironment, the different anticancer therapies currently available that target the FGFRs, and the prognostic value of bFGF.

A loss of estrogen signaling in the aromatase deficient mouse penis results in mild hypospadias

Hypospadias is the abnormal opening of the urethra on the underside of the penis and occurs in approximately 1/125 live male births worldwide. The incidence rate of hypospadias has dramatically increased over the past few decades. This is now attributed, at least in part, to our exposure to endocrine-disrupting chemicals (EDCs) which alter the hormonal signals required for development of the penis. In humans androgens are the main drivers of fusion of the urethral folds to form the urethra within the shaft of the penis, a process required for termination of the urethra in its normal location at the tip of the penis. However, recent research has suggested that estrogen also plays a role in this process. To better understand how EDCs impact urethral development it is essential that we understand the normal function of hormones during development of the penis. To define the role of estrogen in urethral development we examined development of the penis in the aromatase (Cyp19a1) Knockout (ArKO) mouse strain in which endogenous estrogen production is completely ablated. We found that the ArKO penis had a mild hypospadias phenotype. The developing ArKO postnatal penis displayed an early disruption in preputial development, which likely causes the mild hypospadias observed in adults. Using qPCR, we found altered expression of keratin genes and key urethral patterning genes in response to the disrupted estrogen signaling. The hypospadias phenotype was almost identical to that reported for the estrogen receptor α (ERα) knockout confirming that ERα is the predominant receptor for mediating estrogen action during development of the mouse penis. Our results show that estrogen is required for normal prepucial development and placement of the mature urethral opening at the distal aspect of the penis. We also identified several genes which are potential downstream targets of estrogen during normal urethral closure. With this knowledge, we can now better understand how anti-estrogenic as well as estrogenic EDCs disrupt urethral closure to cause mild hypospadias in both mice and humans.

FGF-2 and FGFR-1 might be independent prognostic factors in oral tongue squamous cell carcinoma

AIMS

Fibroblast growth factor (FGF)-2 and fibroblast growth factor receptor (FGFR)-1 are associated with tumour invasiveness, cell proliferation, angiogenesis, and metastasis. The aims of this study were to investigate FGF-2 expression and FGFR-1 expression in oral epithelial dysplasia (OED) and oral tongue squamous cell carcinoma (OTSCC), and their correlation with OTSCC patients' prognosis.

METHODS AND RESULTS

One hundred and sixty-seven cases were retrospectively selected, including 85 surgical specimens of patients with OTSCC, 46 incisional biopsies of OTSCC, and 36 incisional biopsies of OED. Tissue sections were subjected to immunohistochemical staining for FGF-2 and FGFR-1, and digitally scored. Elevated scores of FGF-2 and FGFR-1 immunostaining were associated with high-grade OEDs. FGF-2 positivity in the stroma was associated with vascular invasion and a worse prognosis, in both overall survival (OS) and disease-free survival (DFS) analyses, in univariate and multivariate models. FGFR-1 positivity in the stroma was correlated with lymph node metastasis and distant metastasis. FGFR-1 expression in either the malignant cells or the stroma was strongly correlated with shorter OS and DFS.

CONCLUSIONS

Taken together, our findings suggest that increased FGF-2 expression and increased FGFR-1 expression are associated with high-grade OEDs, and are correlated with the presence of metastasis and adverse outcomes in OTSCC patients.

Fibroblast Growth Factor (FGF-2) and Its Receptors FGFR-2 and FGFR-3 May Be Putative Biomarkers of Malignant Transformation of Potentially Malignant Oral Lesions into Oral Squamous Cell Carcinoma

There are several factors like angiogenesis, lymphangiogenesis, genetic alterations, mutational factors that are involved in malignant transformation of potentially malignant oral lesions (PMOLs) to oral squamous cell carcinoma (OSCC). Fibroblast growth factor-2 (FGF-2) is one of the prototypes of the large family of growth factors that bind heparin. FGF-2 induces angiogenesis and its receptors may play a role in synthesis of collagen. FGFs are involved in transmission of signals between the epithelium and connective tissue, and influence growth and differentiation of a wide variety of tissue including epithelia. The present study was undertaken to analyze expression of FGF-2 and its receptors FGFR-2 and FGFR-3 in 72 PMOLs, 108 OSCC and 52 healthy controls, and their role in risk assessment for malignant transformation of Leukoplakia (LKP) and Oral submucous fibrosis (OSMF) to OSCC. Immunohistochemistry was performed using antibodies against FGF-2, FGFR-2 and FGFR-3. IHC results were validated by Real Time PCR. Expression of FGF-2, FGFR-2 and FGFR-3 was upregulated from PMOLs to OSCC. While 90% (9/10) of PMOLs which showed malignant transformation (transformed) expressed FGF-2, only 24.19% cases (15/62) of PMOLs which were not transformed (untransformed) to OSCC expressed FGF-2. Similarly, FGFR-2 expression was seen in 16/62 (25.81%) of untransformed PMOLs and 8/10 (80%) cases of transformed PMOLs. FGFR-3 expression was observed in 23/62 (37.10%) cases of untransformed PMOLs and 6/10 (60%) cases of transformed PMOLs. A significant association of FGF-2 and FGFR-2 expression with malignant transformation from PMOLs to OSCC was observed both at phenotypic and molecular level. The results suggest that FGF-2 and FGFR-2 may be useful as biomarkers of malignant transformation in patients with OSMF and LKP.

Fibroblast growth factor 2 is of prognostic value for patients with locally advanced squamous cell carcinoma of the head and neck

BACKGROUND AND PURPOSE

Patients with locally advanced SCCHN have a poor prognosis. This study investigated the prognostic value of the tumor cell expression of the fibroblast growth factor 2 (FGF-2) in patients treated with surgery followed by radiotherapy.

PATIENTS AND METHODS

The impact of FGF-2-expression and 11 additional potential prognostic factors on loco-regional control (LRC), metastases-free survival (MFS), and overall survival (OS) was retrospectively evaluated in 146 patients. Additional factors included age, gender, performance status, pre-radiotherapy hemoglobin levels, tumor site, histologic grade, T-category, N-category, human papilloma virus (HPV) status, extent of resection, and chemotherapy. Univariate analyses were performed with the Kaplan-Meier method and the log-rank test, multivariate analyses with the Cox proportional hazard model.

RESULTS

On multivariate analysis, improved LRC was significantly associated with FGF-2-negativity [risk ratio (RR): 7.33; 95%-confidence interval (CI): 2.88-19.05; p<0.001], lower T-category (RR: 2.42; 95%-CI: 1.47-4.33; p<0.001), lower N-category (RR: 12.36; 95%-CI: 3.48-78.91; p<0.001), and pre-radiotherapy hemoglobin levels ≥ 12 g/dl (RR: 4.18; 95%-CI: 1.73-10.53; p=0.002). No factor was significantly associated with improved MFS. Lower T-category showed a trend (RR: 1.59; 95%-CI: 0.97-2.82; p=0.069). Better OS was significantly associated with FGF-2-negativity (RR: 5.10; 2.22-11.80; p<0.001), lower T-category (RR: 2.17; 95%-CI: 1.38-3.68; p < 0.001), lower N-category (RR: 3.86; 95%-CI: 1.60-10.85; p=0.002), and pre-radiotherapy hemoglobin levels ≥ 12 g/dl (RR: 3.20; 95%-CI: 1.46-7.30; p=0.004). HPV-positivity showed a trend (RR: 2.36; 95%-CI: n.a.; p=0.054).

CONCLUSIONS

Tumor cell expression of FGF-2 proved to be an independent prognostic factor for LRC and OS. This factor can help personalize treatment and stratify patients in future trials.

Ribosomal protein l19 is a prognostic marker for human prostate cancer

Microquantity differential display analysis of gene expression profiles between benign (PNT2) and malignant (PC3M) human prostate cell lines identified the gene encoding ribosomal protein L19 (RPL19) to be overexpressed in the malignant cells. Northern blot hybridization analysis done on a wide range of human cell lines and tissues confirmed the level of RPL19 mRNA to be 5-fold higher in malignant cell lines and 8-fold higher in malignant tissues, when compared with their benign counterparts. Analysis of RPL19 mRNA expression by in situ hybridization revealed a significant increase of RPL19 expression in a substantial number of prostate cancers. All of the eight normal prostatic tissues were unstained (100%). Of 32 benign prostatic hyperplasia (BPH) tissues, 15 (46.9%) were unstained, 9 (28.1%) stained weakly, and 8 (25%) stained moderately. Among 87 carcinomas, only 7 (8.1%) were unstained, whereas 22 (25.2%) stained weakly, 21 (24.1%) stained moderately, and 37 (42.61%) stained strongly. The intensity of staining of the malignant specimens was significantly higher than that of normal and BPH specimens (chi(2): n = 127, P < 0.001). Gleason scores of the carcinomas correlated with RPL19 expression (chi(2): n = 87, P < 0.001). Kaplan-Meier survival analysis confirmed increased RPL19 expression to be highly predictive of shorter patient survival (P < 0.05), revealing RPL19 to be a sensitive predictor of prostate cancer progression. Expression of this protein could be a valuable marker in prostate cancer diagnosis and patient management.

Ultrastructural changes of the palatal mucosa following application of 4-nitroquinoline-l-oxide (4NQO) in rats subjected to major salivary gland excision

OBJECTIVE

It has been suggested that saliva exerts a protective role against the carcinogenic effect of various substances in the oral cavity. The objective of this study was to examine the ultrastructural changes of the palatal mucosa caused by the application of 4-nitroquinoline-l-oxide (4NQO) in the presence or absence of saliva.

STUDY DESIGN

Wistar-Furth rats subjected and not subjected to total bilateral excision of the major salivary glands were either painted with an aqueous solution of 4NQO or with propylene glycol only (controls). Two animals of each group were humanely killed periodically. The areas of the palatal lesions were immediately sliced and processed for TEM examination.

RESULTS

Ultrastructurally, the progressive changes to squamous cell carcinoma were observed in the animals painted with 4NQO. In the desalivated animals group, the ultrastructural alterations appeared earlier than in the group with salivary glands.

CONCLUSIONS

Saliva appeared to delay but not hinder tumor induction by 4NQO.

Genome-wide aberrations in pancreatic adenocarcinoma

Chromosomal instability, manifesting as copy number alterations (CNAs), is characteristic of pancreatic adenocarcinoma. We used bacterial artificial chromosome (BAC) array-based comparative genomic hybridization (aCGH) to examine the pancreatic adenocarcinoma genome for submicroscopic amplifications and deletions. Profiles of 33 samples (17 first-passage xenografts and 16 cell lines) identified numerous chromosomal regions with CNAs, including losses at 1p36.33 approximately p34.3, 1p13.3 approximately p13.2, 3p26, 3p25.2 approximately p22.3, 3p22.1 approximately p14.1, 4q28.3, 4q31, 4q35.1, 5q14.3, 6p, 6q, 8p23.3 approximately p12, 9p, 9q22.32 approximately q31.1, 13q33.2, 15q11.2, 16p13.3, 17p, 18q11.21 approximately q23 , 19p13.3 approximately p13.12, 19q13.2, 21p, 21q, and 22p, 22q and gains at 7p21.1 approximately p11.2, 7q31.32, 7q33, 8q11.1 approximately q24, 11p13, 14q22.2, 20p12.2, and 20q11.23 approximately q13.33. Novel regions containing CNAs were identified and refined by combining the increased resolution of our BAC CGH array with a statistical algorithm developed for assigning significance values to altered BACs across samples. A subset of array-based CNAs was validated using polymerase chain reaction-based techniques, immunohistochemistry and fluorescence in situ hybridization. BAC aCGH proved to be a powerful genome-wide strategy to identify molecular alterations in pancreatic cancer and to distinguish differences between cell line and xenograft aberration profiles. These findings should greatly facilitate further research in understanding the pathogenesis of this lethal disease, and could lead to the identification of novel therapeutic targets and biomarkers for early detection.

Microvessel density and expression of vascular endothelial growth factor, basic fibroblast growth factor, and platelet-derived endothelial growth factor in oral squamous cell carcinomas

Angiogenesis, the growth of capillary vessels, plays an important role in the metabolic functions of malignant tissues. Tumor growth and malignant transformation are considered to be dominated by uncontrolled angiogenesis. To understand the mechanism of increased vascularity associated with malignant tissues, we immunohistochemically evaluated microvessel density (MVD) and the expression of vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), and platelet-derived endothelial growth factor (PDGF) in oral cancers. Microvessel density did not differ significantly between normal oral mucosa and epithelial dysplasia, but was significantly increased in tumor tissues. Expression of angiogenic factors was not found in normal oral mucosa, but increased in association with increasing vascularity in OSCC tissue. In tumor tissue, angiogenic factor expression correlated with MVD. MVD in OSCC was related to T stage, tumor differentiation, and stage of invasion. VEGF expression also correlated with tumor differentiation and the stage of invasion. These findings suggest that VEGF might play an important role in tumor angiogenesis of OSCC.

Basic Fibroblast Growth Factor Expression following Surgical Delay of Rat Transverse Rectus Abdominis Myocutaneous Flaps

Partial transverse rectus abdominis myocutaneous (TRAM) flap loss in breast reconstruction can be a devastating complication for both patient and surgeon. Surgical delay of the TRAM flap has been shown to improve flap viability and has been advocated in "high-risk" patients seeking autogenous breast reconstruction. Despite extensive clinical evidence of the effectiveness of surgical delay of TRAM flaps, the mechanisms by which the delay phenomenon occurs remain poorly understood. To examine whether angiogenic growth factors such as basic fibroblast growth factor (bFGF) may play a role in the delay phenomenon, the authors studied the expression of bFGF in rat TRAM flaps subjected to surgical delay. Thirty-five female Sprague-Dawley rats were randomly assigned to one of four TRAM flap groups: no delay (n = 6), 7-day delay (n = 12), 14-day delay (n = 10), or 21-day delay (n = 7). Surgical delay consisted of incising skin around the perimeter of the planned 2.5 x 5.0-cm TRAM flap followed by ablation of both superior epigastric arteries and the left inferior epigastric artery, thus preserving the right inferior epigastric artery (the nondominant blood supply to the rectus abdominis muscle of the rat). TRAM flaps were then elevated after 7, 14, and 21 days of delay by raising zones II, III, and IV off the abdominal wall fascia. Once hemostasis was assured, the flaps were sutured back in place. All flaps were designed with the upper border of the flap 1 cm below the xiphoid tip. Three days after the TRAM procedure, postfluorescein planimetry was used to determine percent area viability of both superficial and deep portions of TRAM flaps. All rats were euthanized and full-thickness TRAM specimens were taken from zones I, II, III, and IV for enzyme-linked immunoabsorbent assay analysis of bFGF levels. Statistical testing was done by t test (percent viability) and two-way analysis of variance (bFGF levels). All delayed flaps had significantly higher bFGF levels when compared with all nondelayed control flaps (p < 0.05). The bFGF levels were not different in the rats that received TRAM flaps 7, 14, or 21 days after delay surgery. There was also no significant difference in bFGF levels among zones I through IV. Control rats had more peripheral zone necrosis compared with all delayed TRAM rats. All delayed flaps had a significantly higher area of flap viability superficially than nondelayed control flaps (p < 0.05). There was no difference in deep flap viability. Surgical delay of rat TRAM flaps is associated with improved flap viability and significantly elevated levels of bFGF over nondelayed TRAM flaps at postoperative day 3 after TRAM surgery. The increases in bFGF noted at this time point suggests that bFGF may play a role in the improved TRAM flap viability observed after delay surgery. Further investigation is needed to evaluate the role bFGF may play in the delay phenomenon.

Relationship between inducible nitric oxide synthase expression and angiogenesis in primary gallbladder carcinoma tissue

AIM: To explore the relationship between angiogenesis and biological behaviors of primary gallbladder carcinoma (PGBC), the relationship between the expression of inducible nitric oxide synthase (iNOS) and biological behaviors of PGBC and its relationship with the expression of iNOS and angiogenesis of PGBC.

METHODS: The expression of iNOS and micro-vessel density (MVD) were assessed by immunohistochemical method and image analysis system in 40 specimens of PGBC and in 8 specimens of normal gallbladder. The immunostaining results and related clinicopathologic materials were analyzed by statistical methods.

RESULTS: MVD in PGBC was significantly higher than that in normal gallbladder tissue (46 ± 14 vs 14 ± 6, P < 0.05), and was not related with age, gender, tumor size and histological type. MVD of poorly and undifferentiated tumor tissues was higher than that of moderately-differentiated and well-differentiated tumor tissues (52 ± 9 vs 43 ± 9 vs 33 ± 6, P < 0.01). MVD of Nevin IV and V stages was higher than that of Nevin I, II and III stages (52 ± 8 vs 37 ± 13, P < 0.01). MVD of cases with lymphatic or liver metastasis was significantly higher than that without liver metastasis (55 ± 6 vs 42 ± 10, P < 0.05) or lymphatic metastasis (53 ± 8 vs 38 ± 8, P < 0.01). The positive level index (PLI) of iNOS in PGBC was 0.435 ± 0.134, and was not related with age, gender, tumor size, histological type, differentiation and clinical stage of PGBC. The PLI of iNOS in cases with lymphatic metastasis was higher than that without lymphatic metastasis (0.573 ± 0.078 vs 0.367 ± 0.064, P < 0.01). The PLI of iNOS in cases with liver metastasis was higher than that without liver metastasis (0.533 ± 0.067 vs 0.424 ± 0.084, P < 0.05). There was a significant correlation between PLI of iNOS and MVD in PGBC (P < 0.05).

CONCLUSION: Angiogenesis of PGBC is significantly related to the biological behaviors of PGBC. The expression of iNOS is related to the biological behaviors of PGBC. The detection of MVD and the expression of iNOS in PGBC can be used as parameters to determine the degree of malignancy and prognosis.

Fibroblast and epidermal growth factors modulate proliferation and neural cell adhesion molecule expression in epithelial cells derived from the adult mouse tongue

Lingual epithelial cells, including those of the taste buds, are regularly replaced by proliferative stem cells. We found that integrin beta(1), a keratinocyte stem cell marker, was expressed at the basal layer and taste buds of adult mouse tongue epithelium. We purified and cultured integrin beta(1)-positive cells (termed KT-1 cells), whose growth was stimulated by epidermal growth factor (EGF) and basic fibroblast growth factor (FGF-2). FGF-2 stimulation induced translocation of the FGF type I receptor (FGFR1) into nuclei, suggesting that the growth-stimulating effect of FGF-2 was mediated through FGFR1. EGF and FGF-2 also regulated cell surface expression of the neural cell adhesion molecule (N-CAM) in KT-1 cells. Anti-N-CAM antibody immunoreactivity was restricted to the gustatory epithelium and the nerves in the tongue epithelium, giving rise to the possibility that KT-1 may contain gustatory epithelial cells. KT-1 cells may thus be useful for analyzing the factors that regulate the growth and differentiation of lingual and gustatory epithelial cells in vitro.

Immunohistochemical localization of growth factors fibroblast growth factor-1 and fibroblast growth factor-2 and receptors fibroblast growth factor receptor-2 and fibroblast growth factor receptor-3 in normal oral epithelium, epithelial dysplasias, and squamous cell carcinoma

OBJECTIVES

Fibroblast growth factors (FGFs) and their receptors (FGFRs) have been identified in a variety of carcinomas, but there are few studies concerning their presence in oral cancers. The objective of this study was to determine whether FGF-1, FGF-2, and high affinity receptors FGFR2 and FGFR3 are present in the pathogenesis of oral epithelial dysplasias and oral squamous cell carcinoma.

STUDY DESIGN

Sections from formalin-fixed, paraffin-embedded samples of oral normal mucosa (n = 14), epithelial dysplasia (n = 20), carcinoma in situ (n = 10), and squamous cell carcinoma (n = 12) were tested for cytoplasmic staining by standard in situ immunohistochemistry with antibodies for FGF-1, FGF-2, FGFR2, and FGFR3.

RESULTS

Staining for FGF-1 is decreased or lost in the development of epithelial dysplasia and carcinoma. Staining for FGF-2 showed increased intensity (although not statistically significant) in oral epithelial dysplasias and squamous cell carcinomas and showed a significant increased expression in the upper layers of dysplasias and stratum spinosum-like cells in squamous cell carcinomas. Staining for FGFR2 showed a statistically significant increase in intensity in all layers of epithelial dysplasias and squamous cell carcinomas. Staining for FGFR3 was found in the upper stratum spinosum cells of normal and dysplastic epithelium and well-differentiated squamous cells in squamous cell carcinomas, with a statistically significant increase in staining intensity in dysplastic and carcinomatous tissues.

CONCLUSIONS

The loss of FGF-1 is consistent with loss of differentiation in dysplasias and some squamous cell carcinomas. Changes in the localization of FGF-2 and FGFR2 into upper epithelial layers with increasing dysplasia suggest increased mitotic potential of high level cells. The co-localization of FGF-2 and its high affinity receptors in neoplastic tissues suggests an autocrine mechanism of influence on carcinogenesis.