Apoptosis, angiogenesis and proliferation: trifunctional measure of tumour response to radiotherapy for oral cancer

Beneficial effect of KYP-2047, a propyl-oligopeptidase inhibitor, on oral squamous cell carcinoma

Oral squamous cell-carcinoma (OSCC) is a common cancer which arises from the alveolar ridge, buccal mucosa, and tongue. Among OSCC, the incidence of tongue squamous cell-carcinoma (TSCC) is growing all over the world. Oral carcinogenesis has been linked to genetic mutations, chromosomal aberrations and viral factors. Apoptosis and angiogenesis play a key role in the development of oral cancer. Therefore, it is very important discover new therapeutic strategies to counteract oral cancer progression. This study aimed to investigate the effect of KYP-2047 in an in vitro model of TSCC and in vivo CAL27-xenograft model. Our results demonstrated that KYP-2047 was able to reduce TSCCs cell viability at the concentrations of 50 μM and 100 μM. Additionally, KYP-2047 was able to increase Bax, Bad and caspase-3 expression, whereas Bcl-2 and p53 expression were reduced. Moreover, KYP-2047 significantly reduced vascular-endothelial-growth-factor (VEGF) and endothelial-nitric-oxide-synthase (eNOS) expression. In the vivo xenograft model, KYP-2047 at doses of 1 and 5 mg/kg significantly reduced tumor burden and tumor weight, decreasing also angiogenesis markers VEGF and eNOS. Moreover, KYP-2047 increased Bax and reduced Bcl2 expressions. Thus, KYP-2047 could represent a potential therapeutic treatment to counteract tongue oral-cancer growth, thanks its abilities to modulate angiogenesis and apoptosis pathways.

Hypoxia-inducible factor 1 and breast cancer metastasis

Accumulating evidence has shown that the hypoxic microenvironment, which is critical during cancer development, plays a key role in regulating breast cancer progression and metastasis. The effects of hypoxia-inducible factor 1 (HIF-1), a master regulator of the hypoxic response, have been extensively studied during these processes. In this review, we focus on the roles of HIF-1 in regulating breast cancer cell metastasis, specifically its effects on multiple key steps of metastasis, such as epithelial-mesenchymal transition (EMT), invasion, extravasation, and metastatic niche formation. We also discuss the roles of HIF-1-regulated non-coding RNAs in breast cancer metastasis, and therapeutic opportunities for breast cancer through targeting the HIF-1 pathway.

Correlation of diffusion-weighted imaging data with apoptotic and proliferation indexes in CT26 colorectal tumor homografts in balb/c mouse

PURPOSE

To investigate whether the percentage of apparent diffusion coefficient (ADC) changes could be used as an imaging marker related to tumor cell apoptotic and Ki-67 proliferation index of tumors.

MATERIALS AND METHODS

Mice bearing CT26 colorectal carcinoma tumors were scanned before radiotherapy, then divided into radiotherapy (n = 24) and control groups (n = 24). Diffusion-weighted imaging (DWI) and anatomic T2WI were performed on six randomly chosen mice in total from two groups at different timepoints after radiotherapy (4, 8, 12 hours, 1, 2, 3, 5, 7 days). After imaging, six animals were sacrificed at each timepoint and histological analyses were undertaken. ADC maps were calculated on a pixel-by-pixel basis using built-in software (Functool, GE). Regions of interest were manually circumscribed for all high-signal areas on lesions observed during DWI. The percentage of ADC changes were calculated at predefined timepoints and compared with the apoptotic and proliferation index from the histological analyses by using the Pearson correlation test.

RESULTS

A significant positive correlation was found between the percentage of ADC changes of the viable tissue and apoptotic index. A significant negative correlation was found between the percentage of ADC changes of the viable tissue and Ki-67 proliferation index.

CONCLUSION

Our results suggest that the percentage of ADC changes can be used as a measurement of cell apoptotic and proliferation index in colorectal carcinoma.

Expression of Bcl-2 family proteins and association with clinicopathological characteristics of oral squamous cell carcinoma

AIMS

To characterize the expression of proteins that inhibit (Bcl-2, Bcl-x, Bcl-xL, Bcl-2-related protein A1, BAG-1) or promote (Bak, Bax, Bim/Bod, Bim-Long, Bad, Bid, PUMA) apoptosis and determine possible correlations between the expression of these proteins and clinicopathological features of oral squamous cell carcinoma (OSCC).

METHODS AND RESULTS

Two-hundred and twenty-nine cases of OSCC, arranged in a tissue microarray, were immunohistochemically analysed. The results demonstrated that the absence of vascular invasion was associated with increased expression of Bak, Bax, Bcl-xL, Bcl-2-related protein and PUMA. Increased expression of Bim/Bod and BAG-1 was associated with the presence of perineural infiltration. An increase in Bid and Bim-Long expression was associated with moderately to well-differentiated tumours. Increased expression of the Bcl-2-related protein and PUMA was associated with tumours occurring in the floor of mouth and increased expression of PUMA was also associated with recurrence of the tumour. Multivariate Cox analysis demonstrated that PUMA and Bim-Long were independent factors in prognosis of OSCC.

CONCLUSIONS

Our results showed the involvement of the Bcl-2 family of proteins in OSCC tumorigenesis and suggest that the expression of apoptotic molecules might be used as a prognostic indicator for OSCC.

Prognostic significance of molecular markers in oral squamous cell carcinoma: a multivariate analysis

BACKGROUND

Multiple marker accumulation impacts tumor progression and biologic phenotypes affect clinical outcome of patients with head and neck cancer. Hence, this study investigated a battery of molecular markers that may help to reflect biologic aggressiveness and predict prognosis.

METHODS

Epidermal growth factor receptor (EGFR), Stat3, H-ras, c-myc, p53, cyclin D1, p16, Rb, Ki-67, and Bcl-2 were localized immunohistochemically in 135 oral squamous cell carcinoma patients to assess prognostic value.

RESULTS

In univariate analysis of total patients, p53, Stat3, and p16 predicted both relapse-free survival (RFS) and overall survival (OS). In Cox multivariate analysis, after adjusting for tumor size, nodal status, and lymphatic permeation, p53 was independently associated with RFS and OS, and p16 with RFS only. In only early-stage patients, in univariate analysis, nuclear Stat3 was significant for RFS and OS.

CONCLUSION

Immunostaining of p53, p16, and Stat3 might serve as potential adjuncts in pathologic evaluation of oral tumors to predict risk of relapse.

[The effect of the microenvironment of head and neck cancers on tumor progression]

In the last 20 years the incidence and mortality of head and neck squamous cell carcinomas showed an increasing rate in Hungary. In our work we examined the microenvironment of head and neck cancers localized in different anatomical regions. Clinical evidence shows that the prognosis of hypopharyngeal tumors is poorer than that of head and neck cancers in other anatomical locations. We investigated if tumor size or vascularity correlates with the biological behavior of these tumors. The results showed that the tumor size of laryngeal cancers in T2 stage were significantly larger than that of hypopharyngeal cancers in T4 stage. Regarding the vascularity or VEGF expression we did not find any difference between these two tumor types, suggesting that the more aggressive behavior of hypopharyngeal cancers is probably due to the invasive phenotype of this tumor, an assumption supported by genomic examination. In a prospective study we examined the relation between the microvascular density and treatment outcome in irradiated head and neck cancer patients. We demonstrated that the decreased vascularity induced by radiotherapy is a predictive marker of treatment success. We have investigated the role of the endocrine environment in tumor progression, determining the hormone receptor status of head and neck cancers using immunohistochemical and molecular methods. Results showed that ER and PGR are expressed in almost half of the examined tumors, and the presence of functional ER was also frequent in these cases (40.3%), while the solitary hormone receptor expression was a rare phenomenon. Expression of hormone receptors in all the examined cases did not show any correlation with patient survival but in the laryngeal/hypopharyngeal group ER positivity was associated with a shortened survival (p=0.0636). In a multicenter phase I/II clinical trial we examined the tumoral and stromal effects of a natural leukocyte interleukin (LI) in oral squamous cell cancers. LI was administered locally in four different doses. The proportion of tumor cell nests and tumor stroma decreased significantly after LI treatment (induction of fibrosis), which was associated with the induction of necrosis. Morphometric determination of Ki-67+ cells showed a tendency of cycling stromal cells to decrease in response to treatment by the different doses of LI, while lower doses of LI produced a temporary increase in cycling tumor cells. Density of intraepithelial neutrophils was higher after LI treatment, and the stromal density of neutrophils was higher in the responder subgroup. In the tumor stroma macrophage density was similar in the treated and control cases, while a significant decrease of these cells was observed intraepithelially. Finally, we were not able to detect CD34+ immunosuppressive mononuclear cells in these tumors. Our examinations supported the theory that the tumor stroma and its components play an important role in tumor progression, and therapeutic modulation of these components can influence the progression.

Cellular profile of the peritumoral inflammatory infiltrate in squamous cells carcinoma of oral mucosa: Correlation with the expression of Ki67 and histologic grading

Background

Squamous cells carcinoma is the most important malignant tumor with primary site in the oral cavity and, given the great exposure of mucosa and lips to the etiologic factors of this neoplasm, its incidence is high. Investigation of the prognostic determinants is significant for the expectations of treatment proposal and cure of the patient. The local immune response represented by peritumoral inflammatory infiltrate is a possible prognostic factor.

Methods

In this study, oral mucosa samples of squamous cells carcinoma were analyzed, separated according to their histological classification as well as the phenotypical profile of the cells comprising the peritumoral inflammatory infiltrate was investigated by immunohistochemical method, in addiction, the cell proliferation index via protein Ki67 expression was determinated.

Results

The T lymphocytes made up most of this inflammatory infiltrate, and among these cells, there was a predominance of T CD8 lymphocytes relative to the T CD4 lymphocytes. The B lymhocytes were the second most visualized leucocyte cell type followed by macrophages and neutrophils. The immunohistochemical assessment of Ki-67 positive cells revealed a greater expression of this protein in samples of undifferentiated squamous cells carcinoma.

Conclusion

The results suggest that the cellular immune response is the main defense mechanism in squamous cells carcinoma of oral mucosa, expressed by the large number of T lymphocytes and macrophages, and that the greatest intensity of local response may be associated with the best prognosis.

VEGF signaling inhibitors: more pro-apoptotic than anti-angiogenic

The vascular endothelial growth factor (VEGF) family of polypeptide growth factors regulates a family of VEGF receptor (VEGFR) tyrosine kinases with pleiotropic downstream effects. Angiogenesis is the best known of these effects, but additional VEGF-dependent actions include increased vascular permeability, paracrine/autocrine growth factor release, enhancement of cell motility, and inhibition of apoptosis. In theory, therapeutic inhibition of angiogenesis should reduce tumor perfusion and thus increase tumor hypoxia and chemoresistance, but in clinical practice the VEGF antibody bevacizumab acts as a broad-spectrum chemosensitizer. Since VEGFR expression occurs in many tumor types, such chemosensitization is more readily explained by direct inhibition of tumor cell survival signals than by indirect stromal/vascular effects. The emerging model of anti-VEGF drug action being mediated primarily by tumoral (as distinct from endothelial) VEGFRs has clinically important implications for optimizing the anti-metastatic efficacy of this expanding drug class.

Hypoxia: importance in tumor biology, noninvasive measurement by imaging, and value of its measurement in the management of cancer therapy

PURPOSE

The Cancer Imaging Program of the National Cancer Institute convened a workshop to assess the current status of hypoxia imaging, to assess what is known about the biology of hypoxia as it relates to cancer and cancer therapy, and to define clinical scenarios in which in vivo hypoxia imaging could prove valuable.

RESULTS

Hypoxia, or low oxygenation, has emerged as an important factor in tumor biology and response to cancer treatment. It has been correlated with angiogenesis, tumor aggressiveness, local recurrence, and metastasis, and it appears to be a prognostic factor for several cancers, including those of the cervix, head and neck, prostate, pancreas, and brain. The relationship between tumor oxygenation and response to radiation therapy has been well established, but hypoxia also affects and is affected by some chemotherapeutic agents. Although hypoxia is an important aspect of tumor physiology and response to treatment, the lack of simple and efficient methods to measure and image oxygenation hampers further understanding and limits their prognostic usefulness. There is no gold standard for measuring hypoxia; Eppendorf measurement of pO(2) has been used, but this method is invasive. Recent studies have focused on molecular markers of hypoxia, such as hypoxia inducible factor 1 (HIF-1) and carbonic anhydrase isozyme IX (CA-IX), and on developing noninvasive imaging techniques.

CONCLUSIONS

This workshop yielded recommendations on using hypoxia measurement to identify patients who would respond best to radiation therapy, which would improve treatment planning. This represents a narrow focus, as hypoxia measurement might also prove useful in drug development and in increasing our understanding of tumor biology.

The effect of ZD1839 (Iressa), an epidermal growth factor receptor tyrosine kinase inhibitor, in combination with cisplatin, on apoptosis in SCC-15 cells

The aim of this study was to determine the effect of ZD1839 on growth and apoptosis in SCC-15 (a human head and neck cancer cell line) lone, or in combination with cisplatin. High expression of the epidermal growth factor receptor has been implicated in the development of squamous cell carcinomas of head and neck. ZD1839 ('Iressa') is an orally active, selective epidermal growth factor receptor tyrosine kinase inhibitor that blocks signal transduction pathways implicated in proliferation and survival of cancer cells, and other host-dependent processes promoting cancer growth. Here, growth arrest was observed with 3.64 microm ZD1839. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (sMTT) viability assay revealed a significant decrease (P < 0.001) in the percentage of surviving cells upon treatment with ZD1839 and cisplatin compared with cisplatin or ZD1839 on their own. Combined therapy of 3.64 microm ZD1839 for 24 h, prior to administration of 100 microm cisplatin, significantly (P < 0.001) and additively increased the cytotoxicity effect of cisplatin. p53-independent apoptosis was seen with cisplatin treatment, a novel finding. These data support the use of ZD1839 in anti-cancer therapy, and particularly in combination therapy. Cisplatin may induce p53-independent apoptosis. Over-expression of Bcl-2 in head and neck squamous cell carcinoma tumour cell lines is unlikely to be a general mechanism to protect these cells from apoptosis.

The quantification of angiogenesis in relation to metastasis in oral cancer: a review

Tumours need vessels to grow into clinically significant dimensions, and to metastasize. Varying results have been reported for the relation between angiogenic activity in oral carcinomas, and the occurrence of metastasis. Quantification of microvessels in tissue sections is mostly used to assess angiogenesis, but appears subject to biases as reflected in contradicting reports. Especially the choice of immunohistochemical staining technique appears pivotal. Although microvessel density measurements (MVD) appear promising for other tumour types, in oral carcinomas no unambiguous relation could be established. Furthermore, MVD assessment appears more elaborate than expected. New, more time efficient techniques may replace MVD as we know it.

Prognostic and predictive factors in oral squamous cell cancer: important tools for planning individual therapy?

An escalation in the incidence of oral cancer and its attributable mortality has been observed in recent decades in Europe; oral cancer is expected to become a public health problem in the foreseeable future. However, survival rates have remained at a disappointingly stable level despite significant development in the multimodality treatment of the disease. Additionally, due to the limited prognostic value of conventional prognostic factors and the uniformity of treatment strategies, several patients are still over- or under-treated with significant personal and socio-economical impact. Here we review some promising prognostic and predictive markers that can help the clinician to improve prognostic accuracy and define the most appropriate management for the individual patient with oral cancer.

Imbalance between proliferation and apoptosis may be responsible for treatment failure after postoperative radiotherapy in squamous cell carcinoma of the oropharynx

To assess the prognostic value of apoptosis, proliferation and clinical factors in squamous cell carcinoma of the oropharynx after radical surgery and postoperative radiotherapy (RT). Between 1985 and 1995, a total of 82 patients with 84 tumors were entered onto the study. Forty-two primary tumors (50%) involved the tonsils, 23 (27%) the soft palate, and 19 (23%) the base of the tongue. Median age was 52 years (range, 36-73 years). The pT- and pN-categories (UICC 1997) were: T1 (24), T2 (36), T3 (18), T4 (6), N0 (31), N1 (12), N2 (38), NX (8). Histologically clear margins were achieved in all patients by initial surgery. Postoperative RT to the primary and regional lymphatics was given with 60 Gy in 6 weeks and single daily fractions of 2 Gy. The expression of the nuclear Ki-67 labeling index (LI) was investigated by immunostaining using the monoclonal antibody MIB 1 and apoptotic carcinoma cells were identified using the terminal deoxynucleotidyltransferase-(TdT)-mediated dUTP nick end labeling (TUNEL) technique. Median follow-up was 43 months (range, 14-132 months). Overall survival, disease-free survival, and locoregional tumor control rates were 59, 70 and 76% at 5 years. Median values for apoptotic index and Ki-67 labeling were 1.6% (range 0-4.7%), and 20% (range, 0-79%), respectively. Apoptotic index <or=1.6% had a profound negative impact when associated with higher proliferation rates (5-year disease-free survival: 26%) as compared to all other patients with a balance between apoptosis and proliferation (5-year disease-free survival: 66-86%, P=0.003). Additional significant prognostic factors for disease-free survival were: tumor site (tonsils: 83% vs soft palate: 66% vs base of tongue: 49%, P=0.02), duration of RT (<or=47 days: 83% vs >47 days: 55%, P=0.03), Ki-67 LI (<or=20%: 84% vs >20%: 56%, P=0.006). A significant prognostic impact on locoregional control was noted for the duration of RT (P=0.01), tumor site (P=0.02), and the Ki-67 LI (P=0.02). A low apoptotic index together with higher proliferation rates led to unfavourable local control as low as 25% compared to the patients with higher apoptotic index (70-80%, P=0.009). An imbalance between apoptotic index and proliferation may identify patients with squamous cell carcinoma at high risk for local recurrence after surgery and postoperative RT. Prospective observation of these factors in clinical trials is warranted to further elucidate this phenomenon.

Prognostic relevance of molecular markers of oral cancer--a review

The aim of the present article was to review the current knowledge on the prognostic value of tumour marker in the treatment of oral squamous cell carcinoma (OSCC). The literature of the past 5 years (1997-August 2002) was screened. One hundred and sixty-nine articles were included in this review, twenty-nine molecular markers of relevance were identified. Tumour markers were allocated to four groups according to their function: (i) Enhancement of Tumour Growth: Cell cycle acceleration and proliferation, (ii) Tumour Suppression and Anti-Tumour Defence: Immune response and apoptosis, (iii) Angiogenesis, (iv) Tumour Invasion and Metastatic Potential: Adhesion molecules and matrix degradation. Data showed that the prognostic relevance of most tumour markers is still not quite clear. Only 12 of 23 reports on the prognostic relevance of markers for cell cycle acceleration and proliferation indicated a significant association with prognosis while 20 of 29 studies on markers for tumour suppression and anti-tumour response showed prognostic relevance. Markers of angiogenesis exhibited only minor importance for the prognosis and treatment of OSCC. Results on markers of tumour invasion and metastatic potential appeared to be too premature for a statement regarding their prognostic value. In general, the location of markers within the tumour and not their quantitative assessment as such is emphasized. Particularly, the analysis of the invasive front of the tumour with regard to the occurrence of molecular markers is supposed to be of great importance for prognostication.

Cell death regulation in oral squamous cell carcinoma: methodological considerations and clinical significance

In the last three decades, more work has been done on apoptosis and its role in the pathogenesis of many diseases including cancer. In almost all instances of cancer, dysregulation of cell death (apoptosis) and cell proliferation have been found to play a major role in tumourigenesis. A lot of progress has been made on understanding the molecular basis of apoptosis and its regulatory mechanisms. This review focuses on current knowledge on the regulation of apoptosis in oral squamous cell carcinoma, current methodologies and methodological consideration in estimation of cell death in tissue sections and the clinical significance of apoptosis related molecules in progression of oral squamous cell carcinoma.

Expression of p53R2, newly p53 target in oral normal epithelium, epithelial dysplasia and squamous cell carcinoma

Recently, the p53R2 gene has been isolated and shown to play a crucial role in DNA repair after DNA damage. The p53R2 gene encodes the p53 inducible ribonucleotide reductase small subunit 2 homologue, which is part of the p53 pathway. However, the function of p53R2 in human cancer is still unclear. We investigated p53R2 mRNA expression in human oral normal epithelium, epithelial dysplasias and squamous cell carcinomas (SCCs). Surgical or biopsy-proven specimens of 10 normal epithelium, 48 epithelial dysplasias and 63 SCCs were collected in our department. Then, p53R2 was identified by in situ hybridization to visualize and localize the expression of specific mRNAs. The authors examined the p53 gene mutation by polymerase chain reaction-single strand conformation polymorphism analysis. p53, mdm2, p21(WAF1/CIP1) and Ki-67 expression was detected by immunohistochemistry. p53R2 expression was detected in none of ten normal epithelium (0%), ten of 48 dysplasias (20.8%) and 33 of 63 SCCs (52.4%). In oral SCC, the expression of p53R2 was significantly associated with tumor size, lymph node metastasis and histological differentiation (P=0.014, 0.046 and 0.022, respectively). p53R2 expression was significantly associated with p53 abnormality in epithelial dysplasia and SCC (P=0.034 and 0.009, respectively). Of 63 patients, 37 received preoperative radiochemotherapy. p53R2 mRNA expression was significantly associated with the pathologic response to radiochemotherapy (P=0.031). This study suggested that p53R2 expression could be associated with oral carcinogenesis. The presence of p53R2 mRNA expression would be a predictive factor for tumor development, tumor cell differentiation and the sensitivity to radiochemotherapy in oral SCC.