Increased expression of basic fibroblast growth factor in squamous carcinogenesis of the head and neck is less prevalent following smoking cessation

VEGF and bFGF expression and microvessel density of maxillary sinus squamous cell carcinoma in relation to p53 status, spontaneous apoptosis and prognosis

We have previously reported that p53 mutations, loss of bax expression or decreased spontaneous tumor apoptosis were associated with poorer prognoses in maxillary sinus squamous cell carcinoma (SCC)(Cancer 94: 1968-1980, 2002). In the present study, we analyzed tumor angiogenesis monitored by expression of vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF) and tumor microvessel density, in correlation with p53 status, spontaneous apoptosis or disease prognosis in the same group of 70 maxillary sinus SCC patients. Tumor biopsy specimens obtained prior to initiation of treatment were examined for expression of VEGF and bFGF and tumor microvessel density using immunohistological methods. Average vessel density (AVD) (range: 3-75; median: 25) and maximum vessel density (MVD) (range: 4-125; median: 53) were assessed by the number of microvessels stained with anti-CD31 mAb in tumor lesions. VEGF was expressed in 35 (50%) of 70 patients and bFGF was in 43 (61%). Patients with VEGF expression showed significantly higher levels of MVD than those without VEGF expression (57 vs. 38; P=0.019). The VEGF expression was observed more frequently in patients with p53 overexpression and/or mutation than in those with normal p53 status (P=0.048). The MVD inversely correlated with the apoptotic index (AI) defined as the number of single stranded (ss)-DNA-positive cells per 1000 tumor cells (r= -0.23; P=0.022). Patients with neck lymph node and/or distant metastases after surgery showed significantly higher levels of MVD than patients without any metastasis (64 vs. 42; P=0.048). Low histological effectiveness of radiochemotherapy correlated with bFGF expression (P=0.0059). To clarify actual prognostic factors for maxillary sinus SCC, we selected 57 patients treated uniformly with preoperative radiochemotherapy followed by maxillectomy. Kaplan-Meier analysis showed that survival was significantly worse in patients with high MVD (> or =80) than in those with low MVD (<80) (P=0.042). These data suggest that the VEGF expression in association with the p53 overexpression and/or mutations may cause increased microvascularity, decreased spontaneous apoptosis or metastases, while the bFGF expression may be associated with resistance to radiochemotherapy, thereby resulting in poorer prognoses in maxillary sinus SCC. VEGF and bFGF expression and tumor microvessel density in tumor lesions were analyzed in 70 patients with maxillary sinus squamous cell carcinoma. The VEGF expression dependent of p53 overexpression and/or mutations was associated with angiogenesis, decreased spontaneous tumor apoptosis and metastases, while the bFGF expression was associated with resistance to radiochemotherapy, resulting in poor prognosis.

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.

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

The relationship between basic fibroblast growth factor (bFGF), receptors for bFGF and neoangiogenesis was investigated in 51 patients with squamous cell carcinoma of the tongue, 26 of whom had metastatic disease in cervical lymph nodes. Vessels were demonstrated by immunocytochemical labelling for CD34 and expressed as raw counts and volume-weighted counts. bFGF protein and its receptors FGFR1(flg) and FGFR2(bek), were demonstrated using immunocytochemical labelling. In situ hybridisation for bFGF mRNA was performed using a 250-bp digoxigenin-labelled RNA probe. In normal epithelium, the expression of bFGF protein and mRNA was more intense in the basal layer, while receptors for bFGF were expressed more strongly in the superficial parts. In carcinomas, expression of bFGF was greater in the more poorly-differentiated cells, but showed no relation to the overall tumour differentiation. There was strong bFGF expression in tumour-infiltrating lymphocytes. The expression of bFGF receptors was variable, with FGFR2 being particularly high in areas of keratinisation. There were no consistent changes in bFGF or receptor expression between primary carcinomas and their lymph node metastases, and there was no correlation with measures of vascularity or tumour growth pattern. bFGF is synthesised by all squamous carcinomas and has the potential to modulate angiogenesis. However, these data suggest that changes in the expression of bFGF and its receptors are not related to the intensity of neoangiogenesis in lingual carcinomas or their nodal metastases.

Expression of basic fibroblast growth factor protein and its down-regulation by interferons in head and neck cancer

BACKGROUND

Angiogenesis is crucial for tumor growth and metastasis. In several tumors, microvascular density has been shown to correlate with metastasis and aggressiveness. Basic fibroblast growth factor (bFGF) has potent angiogenic activity and has been identified in a wide variety of malignancies including head and neck squamous cell carcinomas (HNSCC). Material and Methods Frozen sections of 50 HNSCC were immunostained for von Willebrand factor and bFGF. Microvessels were counted by light microscopy; bFGF expression was studied at the light and electron microscopic level. Laryngeal cancer cell line HlaC79 was incubated with interferon (IFN) alpha and beta. bFGF quantification was performed by ELISA, and antiproliferative effects were determined by BrdU assay.

RESULTS

The mean number of blood vessels (77.5 +/- 23.7) is significantly increased in HNSCC compared with controls (17.1 +/- 5.9). bFGF protein expression was detected in all HNSCC but not in control tissue. An correlation between bFGF expression and mean number of microvessels was found (p <.001). However, no correlation between bFGF expression and the main clinicopathologic features was shown. The long-term exposure (144 hr) of HNSCC cells to noncytostatic concentrations of IFN alpha and beta (>10 U/mL) down-regulated the protein production of bFGF.

CONCLUSION

bFGF expression and angiogenesis are enhanced in HNSCC. The higher microvessel density in HNSCC with strong bFGF expression supports the importance of bFGF for tumor angiogenesis. IFN alpha and beta treatment leads to a down-regulation of bFGF expression independent of their antiproliferative effects, suggesting that IFN treatment might result in a reduction of angiogenesis in HNSCC.

Angiogenic factors in laryngeal carcinomas: do they have prognostic relevance?

Angiogenesis is a cascade-like mechanism essential for tumour growth and metastasis. Recently developed inhibitors of angiogenesis have already proven their benefit in anticancer treatment. Therefore the existence of angiogenic molecules in individual tumours is of major interest. The factors most frequently contributing to angiogenesis are basic fibroblast growth factor (bFGF), vascular endothelial growth factor (VEGF) and some matrix metalloproteinases (MMPs). In order to evaluate the prognostic significance of these molecules we investigated the distribution pattern of VEGF, bFGF, MMP-2 and MMP-9 in 41 laryngeal carcinomas using immunohistochemical methods. The results were correlated with clinicopathological parameters, i.e. T and N stage, histological grading, freedom from disease, overall survival and microvessel density (MVD). Only VEGF revealed a correlation with MVD (p = 0.01) and a weak association with histological grading (p = 0.06). Even though there is controversy about published data on the prognostic relevance of angiogenic factors, our results suggest that the factors examined in this study are not suitable for prognosis in larynx cancer patients.

Expression of midkine in the early stage of carcinogenesis in human colorectal cancer

It has been suggested that a heparin-binding growth factor, midkine (MK), plays an important role in carcinogenesis because of its frequent overexpression in various malignant tumours. To clarify whether or not MK contributes to the early stage of carcinogenesis, we examined the status of MK mRNA in 20 adenomas with moderate- and severe-grade dysplasia, 28 carcinomas and 28 corresponding normal tissues, by means of Northern blotting. The MK expression level was significantly more elevated in adenomas than in normal tissues (P < 0.001, unpaired Student's t-test). A difference was also observed between carcinomas and the corresponding normal tissues (P < 0.04, paired Student's t-test). Moreover, MK immunostaining was positive in the adenomas with moderate- and severe-grade dysplasia and in the carcinomas, but not in mild-grade dysplasia or in normal tissues. These findings were in line with those on Western blotting. In three patients with both adenomas with moderate- or severe-grade dysplasia and carcinomas, elevated MK expression was observed in the neoplastic lesions. This is the first report of the association of elevated MK expression with the early stage of carcinogenesis in humans.

Expression of the opioid growth factor, [Met5]-enkephalin, and the zeta opioid receptor in head and neck squamous cell carcinoma

Despite the prevalence of cancers of the head and neck, survival rates have not changed in the past few decades. Recent work has implicated peptide growth factors and their receptors in the genesis and progression of head and neck squamous cell carcinoma. Opioid growth factor (OGF, [Met5]-enkephalin) is a tonically active, autocrine and/or paracrine produced, inhibitory factor that influences the growth of normal and abnormal cells and tissues. This peptide interacts with the zeta (zeta) opioid receptor to modulate cellular proliferation, migration, and survival. Both OGF and the zeta receptor are present in mammalian tongue epithelium and skin, and modulate DNA synthesis. In the present study we examined the presence and distribution of OGF and the zeta opioid receptor in the head and neck squamous cell carcinomas from seven individuals. All specimens expressed this growth factor and its receptor regardless of tumor stage, location, and histologic grade. Immunoreactivity for both OGF and the zeta receptor were associated with the cytoplasm but not the nucleus in cells of each of these carcinomas. Our findings that a potent negative growth regulator and its receptor are present in head and neck squamous cell carcinoma lead us to suggest that OGF may modulate the growth of these types of cancers.

Biological staging of head and neck cancer and its role in developing effective treatment strategies

The purpose of a cancer staging system is to encompass all attributes of a tumor that define its life history. We propose a biological staging system which incorporates all of the phases of the natural history of head and neck cancer beginning with the earliest cellular changes extending through the early phase of invasion to the occurrence of metastasis and, finally, culminating in therapeutically refractory disease. This temporally structured system recognizes the importance of constitutional predisposition, and the impact of environmental factors. The intent is to augment the AJCC/UICC staging system and use this system to provide a framework which will easily incorporate current and future advances in basic science, prevention, therapy and palliation which will improve the quality and quantity of life for patients.