Correlation between tumor angiogenesis and expression of thymidine phosphorylase, and patient outcome in uterine cervical carcinoma

Experimental study of Endostar injection concomitant with cryoablation on lung adenocarcinoma A549 xenografts

OBJECTIVE

To explore the inhibiting effect and mechanism of Endostar injection concomitant with cryoablation on lung adenocarcinoma A549 xenografts in nude mice.

MATERIALS AND METHODS

A total of 24 nude mice with subcutaneous xenografts of the A549 cell line were established and divided into 4 groups when the maximal diameters of tumors became 1 cm: control group, Endostar group, cryoablation group and combination group (Endostar concomitant with cryoablation). The nude mice were sacrificed after 21-days treatment, tumour tissues were removed to measure their volume, in situ test of TdT-mediated dUTP nick end labeling (TUNEL) was adopted to determine the cellular apoptosis around freezing injury zones, and immunohistochemical SP test was applied for the detection of micro-vessel density (MVD) and vascular endothelial growth factor (VEGF) expression levels.

RESULTS

At 21-days after treatment, the growth velocities of control group, Endostar group, cryoablation group and combination group were 236.7 ± 51.2%, 220.0 ± 30.6%, 159.5 ± 29.3% and 103.3 ± 25.5% (P<0.01), while cellular apoptosis rates of tumors were 21.7 ± 2.34%, (22.17 ± 1.47)%, 38.3 ± 1.37% and 49.2 ± 1.72%, (P<0.01), respectively, according to the immunohistochemical test. MVD and VEGF expression levels in the combination group were both lower than in other groups (P<0.01), also being positively related (r=0.925, P<0.01).

CONCLUSIONS

Endostar can significantly improve the inhibitory effects of cryoablation on xenografts of lung adenocarcinoma A549, and the mechanism is probably associated with its function as an inhibitor of tumour neo-angiogenesis through down-regulating VEGF expression.

The effect of chemotherapy or radiotherapy on thymidine phosphorylase and dihydropyrimidine dehydrogenase expression in cancer of the uterine cervix

OBJECTIVE

Levels of 5-FU metabolic or related enzymes, particularly thymidine phosphorylase (TP) and dihydropyrimidine dehydrogenase (DPD), have been investigated in various cancer types, including uterine cervical cancer. Intratumoral TP levels have been reported to increase in response to several chemotherapeutic agents or irradiation in both xenografts and clinical studies. In cervical cancer, however, only a few studies about changes in TP and DPD expression associated with cancer treatment have been published. We evaluated the effect of chemotherapy and/or irradiation on TP and DPD expression in cervical squamous cell carcinoma.

STUDY DESIGN

Of 27 patients in this study, 12 patients underwent neoadjuvant chemotherapy consisting of nedaplatin, ifosfamide, and/or peplomycin followed by radical surgery, and 15 patients underwent radiotherapy (n=8) or chemoradiotherapy with nedaplatin (n=7) as initial treatment. Tumor specimens were obtained from biopsies acquired before treatment and after administration of chemotherapy (2 weeks after the first and second cycles), and after irradiation with 10 Gy, 20 Gy, and 30 Gy. These specimens were used to measure TP and DPD levels by ELISA.

RESULTS

In the 12 patients who received neoadjuvant chemotherapy, intratumoral TP and DPD levels did not change. In contrast, in the 15 patients who underwent radiotherapy or chemoradiotherapy with nedaplatin, TP or DPD expression appeared to be slightly increased or decreased, respectively, after irradiation with 20 Gy, and consequently the TP/DPD ratio was significantly higher after irradiation with 20 Gy than before irradiation.

CONCLUSIONS

These results suggest a clinical advantage of chemoradiotherapy with capecitabine or doxyfluridine over radiotherapy alone via the elevation of the TP/DPD ratio in cervical squamous cell carcinoma. However, no advantage of combination chemotherapy with these 5-FU derivatives was demonstrated. Therefore, further evaluation with a larger number of patients or with other chemotherapeutic agents is required to confirm these observations.

Vascular endothelial growth factor and thymidine phosphorylase expression in salivary gland tumors with distinct metastatic behavior

BACKGROUND

Metastasis of salivary gland tumors has a negative impact on survival. Angiogenesis and its factors are potential markers for predicting metastasis in different malignant tumors, but this is not the case for salivary gland tumors.

METHODS

Salivary gland tumors of distinct biologic behavior were analyzed according to the semiquantitative immunoexpression of vascular endothelial growth factor (VEGF) and thymidine phosphorylase (TP).

RESULTS

Vascular endothelial growth factor expression was predominantly weak in benign tumors. Weak TP expression was observed in 100% cases of benign tumors and in 74.3% of primary malignant tumors. High VEGF and TP expression levels were significantly associated with primary malignant tumors but not with primary non-metastasizing and primary metastasizing malignant tumors or with subtypes of malignant tumors.

CONCLUSIONS

Vascular endothelial growth factor and TP expression levels discriminate benign and malignant tumors but cannot predict metastasis from non-metastasizing tumors.

Epstein-Barr virus latent membrane protein 1 induces the chemotherapeutic target, thymidine phosphorylase, via NF-kappaB and p38 MAPK pathways

High thymidine phosphorylase (TP) expression is significantly correlated with poor prognosis in patients with nasopharyngeal carcinoma (NPC). NPC is an Epstein-Barr Virus (EBV)-associated cancer in which the EBV-encoded oncogene product, latent membrane protein 1 (LMP1), is expressed in approximately 60% of tumor tissues. However, no previous study has examined whether LMP1 is involved in up-regulating TP expression in NPC tissues. We herein show that LMP1 expression is correlated with TP expression in tumor cells, as examined by quantitative RT-PCR and immunohistochemical staining. We further show that the CTAR1 and CTAR2 domains of LMP1 mediate TP induction, as demonstrated by quantitative RT-PCR and Western blot analyses using LMP1 deletion and site-specific mutants. Mechanistically, LMP1-mediated TP induction is abolished by inhibitors of NF-kappaB and p38 MAPK, dominant-negative IkappaB and p38, and siRNA-mediated knockdown of p38 MAPK. Clinically, there were significant correlations among the expression levels of TP, activated p65, and phospho-p38 MAPK in NPC biopsy samples. Functionally, LMP1-mediated induction of TP expression enhanced the sensitivity of NPC cells to the chemotherapeutic prodrug, 5'-DFUR. Our results provide new insights into the roles of LMP1-mediated NF-kappaB and p38 MAPK signaling pathways in TP induction, potentially suggesting new therapeutic strategies for the treatment of NPC.

The dual role of thymidine phosphorylase in cancer development and chemotherapy

Thymidine phosphorylase (TP), also known as "platelet-derived endothelial cell growth factor" (PD-ECGF), is an enzyme, which is upregulated in a wide variety of solid tumors including breast and colorectal cancers. TP promotes tumor growth and metastasis by preventing apoptosis and inducing angiogenesis. Elevated levels of TP are associated with tumor aggressiveness and poor prognosis. Therefore, TP inhibitors are synthesized in an attempt to prevent tumor angiogenesis and metastasis. TP is also indispensable for the activation of the extensively used 5-fluorouracil prodrug capecitabine, which is clinically used for the treatment of colon and breast cancer. Clinical trials that combine capecitabine with TP-inducing therapies (such as taxanes or radiotherapy) suggest that increasing TP expression is an adequate strategy to enhance the antitumoral efficacy of capecitabine. Thus, TP plays a dual role in cancer development and therapy: on the one hand, TP inhibitors can abrogate the tumorigenic and metastatic properties of TP; on the other, TP activity is necessary for the activation of several chemotherapeutic drugs. This duality illustrates the complexity of the role of TP in tumor progression and in the clinical response to fluoropyrimidine-based chemotherapy.

Enzymatic activities of uridine and thymidine phosphorylase in normal and cancerous uterine cervical tissues

In this study, the preliminary analyses were conducted of enzymatic activities of uridine phosphorylase (UP) and thymidine phosphorylase (TP) in normal tissues and cancer tissues of the uterine cervix. The study was performed on 27 patients of cervical cancer, treated first in our hospital. Normal cervical tissues obtained from 15 patients undergoing hysterectomy for benign diseases were used as controls. The supernatant of the homogenated cervical tissues and the stroma (5-FU and ribose-1-P or deoxyribose-1-P) were analyzed by high performance liquid chromatography, and then the UP and TP activities calculated. TP activity was significantly greater than UP activity (P < 0.0001). Both UP and TP showed significantly greater activity in cancer tissues than in normal tissues (P < 0.0001). In the TP activity of the cancer tissues, there was no significant difference among the histological types, while the TP activity tended to be significantly higher in the cases with lymph node metastasis. These results showed that the TP-mediated route seemed important as the 5FU metabolic pathway in the uterine cervical tissues, and TP enzymatic activity might be associated with lymph node metastasis.

Expression of thymidine phosphorylase as an effect prediction factor for uterine cervical squamous cell carcinoma after radiotherapy: an immunohistochemical study

Prognoses in cases of uterine cervical squamous cell carcinoma treated with radiotherapy were investigated in association with immunohistochemical expression of an angiogenic factor, thymidine phosphorylase (TP). Forty-six cases of uterine cervical squamous cell carcinoma mainly treated with radiotherapy during 1992-2001 at our clinic were studied. All were diagnosed as stages IIB to IVA. Paraffin-embedded biopsy specimens excised before radiotherapy were stained immunohistochemically using anti-TP monoclonal antibody. The extent of staining in both tumor and interstitial cells was graded as (-), (+/-), (+), and (2+). Specimens with TP expression levels of (2+) and (+) were regarded as positively stained and those with TP expression levels of (+/-) and (-) as negatively stained. The efficacy of radiotherapy in both groups was analyzed by the Kaplan-Meier method. With tumor cells, 5-year survival rates for the positive (n= 38) and negative (n= 8) staining groups were 73.9% and 42.9%, respectively; the rate being significantly higher for the TP-positive group (log rank, P= 0.0096). Contrarily, with staining for interstitial cells, the 5-year survival rates for the positive (n= 20) and negative (n= 26) staining groups were 74.1% and 64.6%, respectively, with no significant difference (log rank, P= 0.406). The efficacy of radiotherapy in the group with positive staining of tumor cells was significantly better than in the negative staining group. Immunohistochemical expression of TP in tumor cells is suggested as a useful prognostic factor for uterine cervical squamous cell carcinomas treated with radiotherapy. Choosing therapy for individual cases by referring to factors including TP expression should contribute to an improved prognosis.

Angiotensin II type 1 receptor expression in ovarian cancer and its correlation with tumour angiogenesis and patient survival

Angiotensin II, a main effector peptide in the renin–angiotensin system, acts as a growth-promoting and angiogenic factor via type 1 angiotensin II receptors (AT₁R). We have recently demonstrated that angiotensin II enhanced tumour cell invasion and vascular endothelial growth factor (VEGF) secretion via AT₁R in ovarian cancer cell lines in vitro. The aim of the present study was to determine whether AT₁R expression in ovarian cancer is correlated with clinicopathological parameters, angiogenic factors and patient survival. Immunohistochemical staining for AT₁R, VEGF, CD34 and proliferating cell nuclear antigen (PCNA) were analysed in ovarian cancer tissues (n=67). Intratumour microvessel density (MVD) was analysed by counting the CD34-positive endothelial cells. Type 1 angiotensin II receptors were expressed in 85% of the cases examined, of which 55% were strongly positive. Type 1 angiotensin II receptors expression was positively correlated with VEGF expression intensity and MVD, but not with histological subtype, grade, FIGO stage or PCNA labelling index. In patients who had positive staining for AT₁R, the overall survival and progression-free survival were significantly poor (P=0.041 and 0.017, respectively) as compared to those in patients who had negative staining for AT₁R, although VEGF, but not AT₁R, was an independent prognostic factor on multivariate analysis. These results demonstrated that AT₁R correlated with tumour angiogenesis and poor patient outcome in ovarian cancer, suggesting its clinical potential for a novel molecular target in strategies for ovarian cancer treatment.

No relationship between thymidine phosphorylase (TP, PD-ECGF) expression and hypoxia in carcinoma of the cervix

The expression of hypoxia-regulated genes promotes an aggressive tumour phenotype and is associated with an adverse cancer treatment outcome. Thymidine phosphorylase (TP) levels increase under hypoxia, but the protein has not been studied in association with hypoxia in human tumours. An investigation was made, therefore, of the relationship of tumour TP with hypoxia, the expression of other hypoxia-associated markers and clinical outcome. This retrospective study was carried out in patients with locally advanced cervical carcinoma who underwent radiotherapy. Protein expression was evaluated with immunohistochemistry. Hypoxia was measured using microelectrodes and the level of pimonidazole binding. There was no relationship of TP expression with tumour pO₂ (r=−0.091, P=0.59, n=87) or pimonidazole binding (r=0.13, P=0.45, n=38). There was no relationship between TP and HIF-1α, but there was a weak borderline significant relationship with HIF-2α expression. There were weak but significant correlations of TP with the expression of VEGF, CA IX and Glut-1. In 119 patients, the presence of TP expression predicted for disease-specific (P=0.032) and metastasis-free (P=0.050) survival. The results suggest that TP is not a surrogate marker of hypoxia, but is linked to the expression of hypoxia-associated genes and has weak prognostic power.

Transcriptional expression of the genes implicated in angiogenesis and tumor invasion in cervical carcinomas

OBJECTIVE

Co-expression patterns of the genes implicated in angiogenesis and tumor invasion in cervical carcinoma cells were investigated together with invasive activity of tumor cells. Transcript levels of those genes were also compared between tumor cells and normal cervical tissues.

METHODS

Real-time quantitative RT-PCR analysis was conducted on selected 11 genes (total VEGF-A, VEGF(121), VEGF(165), VEGF(189), VEGF-B, C and D, bFGF, dThdPase, MMP-2 and uPA) using 11 cervical carcinoma cell lines and 14 normal cervical tissues. Protein expression of VEGF-C and MMP-2 and invasive activity of tumor cells were evaluated for each cell line by sandwich ELISA and haptoinvasion assay, respectively.

RESULTS

Gene co-expression analysis revealed the significant correlation between angiogenic factors and proteinases in malignant but not in normal cervical samples. Gene or protein expression levels of VEGF-C and MMP-2 were well correlated with the number of invaded tumor cells. VEGF-A splicing variants were increased in malignant compared to normal cervical samples but not associated with the invasive activity of the cells.

CONCLUSION

VEGF-C and MMP-2 were closely related to invasive phenotype of tumor cells, whereas VEGF-A isoforms were considered to be involved in cervical carcinogenesis.

Coexpression of cyclooxygenase-2 and thymidine phosphorylase as a prognostic indicator in patients with FIGO stage IIB squamous cell carcinoma of uterine cervix treated with radiotherapy and concurrent chemotherapy

PURPOSE

To evaluate the prognostic significance of thymidine phosphorylase (TP) and coexpression of cyclooxygenase-2 (COX-2)/TP, and to investigate the relationship between COX-2 and TP expression in squamous cell carcinoma of the uterine cervix.

METHODS AND MATERIALS

Cancer specimens from 75 patients with International Federation of Gynecology and Obstetrics Stage IIB squamous cell carcinoma of the uterine cervix who had undergone radiotherapy and concurrent chemotherapy were immunohistochemically stained with COX-2 and TP antibodies and scored. The prognostic significance of their expression status, and the relationship between COX-2 and TP was investigated.

RESULTS

TP predominantly stained cytoplasm and the cell membrane of the tumor cells mainly in a diffuse and intense manner. TP was negative (<10% distribution) in 17%, 1+ (10-50%) in 25%, and 2+ (>50%) in 57% of patients. TP overexpression was related to a marginal prognostic significance of a poor 5-year overall survival (p = 0.082, log-rank test) and a high locoregional recurrence rate (p < 0.1, chi-square test). COX-2 and TP coexpression was observed in 24% of patients and was significantly related to poor 5-year disease-free and overall survival rates (p = 0.0083 and p = 0.025, respectively), a high pelvic lymph node involvement rate, a poor response to treatment, and a greater incidence of locoregional recurrence (p < 0.05). By multivariate analyses, only COX-2, TP, and coexpression of COX-2/TP were significant independent prognostic indicators of patient survival. All tumors showed 1+ or 2+ TP expression when COX-2 was positive, and no tumor expressed COX-2 when TP was negative (p = 0.03). In contrast, 77% of tumors expressed 1+ or 2+ TP without the synchronous expression of COX-2.

CONCLUSIONS

Thymidine phosphorylase expression or COX-2/TP coexpression may be used as a molecular prognostic marker for squamous cell carcinoma of the uterine cervix. TP appears to be an important downstream molecule of COX-2 during angiogenesis and may be a new target for the treatment of uterine cervical cancer.

High level concentration of pyrimidine nucleoside phosphorylase in esophageal squamous cell carcinoma but no correlation with clinicopathological parameters

Pyrimidine nucleoside phosphorylase (PyNPase) converts 5'-deoxy-5-fluorouridine to 5'-fluorouracil, which exerts an anticancer effect before being catabolized by dihydropyrimidine dehydrogenase (DPD). Recently, PyNPase has been shown to be identical to a potent angiogenic factor, platelet-derived endothelial cell growth factor. We analyzed the concentration of PyNPase and DPD in 33 patients with esophageal squamous cell carcinoma in fresh-frozen samples by enzyme-linked immunosorbent assay. In addition, we evaluated the clinical significance and prognostic value of PyNPase expression in esophageal carcinoma. The PyNPase concentration of tumor tissue was statistically higher than that of normal tissue of the esophagus (248 +/- 146 U/mg protein vs 73 +/- 63 U/mg protein, P = 0.0001), whereas DPD showed no difference (90 +/- 62 U/mg protein vs 88 +/- 62 U/mg protein, P = 0.825). The ratio of PyNPase to DPD of tumor tissue was statistically higher than that of normal tissue of the esophagus (3.3 vs 0.95, P = 0.0001). There were no significant differences between the group with high tumor to normal tissue ratios of PyNPase concentration and the low-ratio group in terms of the tumor length, depth, lymph node metastasis, lymph vessel invasion, vascular invasion, stage and survival. In conclusion, 5'-deoxy-5-fluorouridine may be effective on esophageal carcinoma and PyNPase concentration in esophageal carcinoma may not be a useful prognostic marker for patients with esophageal squamous cell carcinoma.

Pd-ECGF positivity correlates with better survival, while iNOS has no predictive value for cervical carcinomas treated with radiotherapy

PURPOSE

Platelet-derived endothelial cell growth factor (PD-ECGF), which has angiogenic activity, is identical to thymidine phosphorylase. Tumor vascularization is considered to be an important prognostic factor. Nitric oxide synthases (NOSs) are a kind of enzyme that generates nitric oxide. Nitric oxide has not only a self defense against neoplastic cells but also tumor growth stimulation by promoting new blood vessel formation. Our purpose was to investigate the correlation between the expression of PD-ECGF or inducible NOS (iNOS) in cancer cells and prognosis.

METHODS AND MATERIALS

Formaldehyde-fixed and paraffin-embedded biopsy specimens excised from 71 cervical squamous cell carcinoma patients who were treated with radiotherapy alone were investigated using an immunohistochemical method.

RESULTS

Cancer cells that were positive for PD-ECGF showed intranuclear and cytoplasmic staining patterns. Of the 71 patients, 40 (56%) were positive for PD-ECGF and 31 (44%) were negative. The 5-year survival of the PD-ECGF-positive patients was significantly better than that of the PD-ECGF-negative patients (p = 0.026). Cancer cells that were positive for iNOS showed a cytoplasmic staining pattern. Twenty-seven patients (38%) were positive for iNOS and 44 (62%) were negative. No significant prognostic correlation was observed between iNOS-positive and iNOS-negative patients.

CONCLUSION

PD-ECGF positivity in cancer cells is a predictive factor for a good prognosis in cervical squamous cell carcinoma treated with radiotherapy alone.

Thymidine phosphorylase expression in oral squamous cell carcinoma

Thymidine phosphorylase (TP), as an enzyme involved in DNA synthesis, catalyzes the reversible conversion of thymidine to thymine. It is also identical to the angiogenic factor, platelet-derived endothelial cell growth factor. We examined TP expression using immunohistochemistry in 66 archival samples obtained from the patients with primary oral squamous cell carcinoma (SCC) and investigated its relation to tumor vascularity, cell proliferation, apoptosis, clinicopathological features and survival. TP expression was identified in cytonucleus and/or cytoplasm in carcinomas, but was not identified in histologically normal epithelia distant to tumor in most cases. No significant difference of microvessel density (MVD) was found between the carcinomas with high TP expression (H-TP) and low TP expression (L-TP). The percentages of proliferative cells marked by Ki-67 staining in H-TP carcinomas was significantly higher than that in L-TP carcinomas (P=0.0222). The apoptotic indice (AI) in H-TP carcinomas tended to be lower than that in L-TP carcinomas (P=0.0723). Moreover, the level of TP expression was significantly correlated the pattern of tumor invasion (P=0.0146) and marginally correlated with lymph nodal metastasis (P=0.0804). Our results suggested that TP enzyme may play a role in promotion of tumor growth in oral SCC, and that its expression can be indicative of tumor aggressiveness in this tumor type.

Intra-tumoural microvessel density in human solid tumours

Over the last decade assessment of angiogenesis has emerged as a potentially useful biological prognostic and predictive factor in human solid tumours. With the development of highly specific endothelial markers that can be assessed in histological archival specimens, several quantitative studies have been performed in various solid tumours. The majority of published studies have shown a positive correlation between intra-tumoural microvessel density, a measure of tumour angiogenesis, and prognosis in solid tumours. A minority of studies have not demonstrated an association and this may be attributed to significant differences in the methodologies employed for sample selection, immunostaining techniques, vessel counting and statistical analysis, although a number of biological differences may account for the discrepancy. In this review we evaluate the quantification of angiogenesis by immunohistochemistry, the relationship between tumour vascularity and metastasis, and the clinicopathological studies correlating intra-tumoral microvessel density with prognosis and response to anti-cancer therapy. In view of the extensive nature of this retrospective body of data, comparative studies are needed to identify the optimum technique and endothelial antigens (activated or pan-endothelial antigens) but subsequently prospective studies that allocate treatment on the basis of microvessel density are required.

Prognostic and predictive value of thymidine phosphorylase activity in early-stage breast cancer patients

The antitumor effects of 5-fluorouracil (5-FU) and its derivatives depend upon the activity of nucleoside metabolic enzymes in tumor tissues. Thymidine phosphorylase (TP) converts 5'-deoxy-5-fluorouridine (5'-DFUR), an intermediate metabolite of capecitabine, to 5-FU. The relationship between TP expression in tumor tissues and patient survival was retrospectively examined in early-stage breast cancer patients treated with either oral 5'-DFUR administered for 6 months or surgery alone in a prospective randomized controlled trial. Thymidine phosphorylase expression in tumor cells and tumor-associated stromal (TAS) cells was examined by immunohistochemistry in 650 tissue samples from patients in this trial (n = 1217). Eight-year follow-up data showed that high TP expression in tumor cells was a significant prognostic indicator of a favorable outcome only for the patients in the 5'-DFUR group. Thus, TP expression was shown to be a predictive factor of 5'-DFUR efficacy. Conversely, a low TP expression in TAS cells was also a potent favorable prognostic indicator. These results on TP status in 2 tumor cell types could provide novel information for predicting prognosis for a patient subgroup, which would receive a probable therapeutic effect from 5'-DFUR, and presumably, from adjuvant therapy of capecitabine in early-stage breast cancer. Determination of TP status might also identify a patient subgroup whose prognosis is quite favorable even without adjuvant therapy. Further investigations on prognostic and predictive implications of TP activity in a clinical setting are warranted.

Correlation between vascular endothelial growth factor-C expression and invasion phenotype in cervical carcinomas

The correlation between vascular endothelial growth factor (VEGF)-C gene expression and in vitro invasive activity and matrix metalloproteinase (MMP)-2 or 9 gene expression and proteolytic activity in 11 cervical carcinoma cell lines, was investigated. Immunohistochemical expression of VEGF-C in 52 cervical carcinoma tissues was also correlated with tumor aggressiveness with respect to clinicopathologic features, tumor vascularity, MMP-2 expression and patient outcome. Expression of VEGF-C mRNA differed remarkably among the cell lines and there was a statistical correlation between VEGF-C gene expression and the number of invaded tumor cells (p = 0.0009) and MMP-2 gene expression and activity (p < 0.05). Anti-VEGF-C antibody inhibited the invasive and proteolytic activity of tumor cells in a concentration-dependent manner. VEGF-C or MMP-2 expression in clinical tissue samples was well correlated with depth of myometrial invasion, endometrial invasion, pelvic lymphnode metastasis and tumor vascularity (p < 0.05) and there was a close relation between VEGF-C and MMP-2 expression (p < 0.0001) in cervical carcinomas. Overall survival rates for 14 patients with strong VEGF-C staining tumors were lower than those for 38 patients with weak VEGF-C staining tumors (p = 0.0132) and VEGF-C tissue status emerged as an independent prognostic parameter (p = 0.0232). These results suggest that VEGF-C expression is closely related to invasion phenotype and affects the patient's survival in cervical carcinomas.

Vascular endothelial growth factor C gene expression is closely related to invasion phenotype in gynecological tumor cells

OBJECTIVE

The correlation between the gene expression of various angiogenic factors and in vitro invasive activity in 16 human gynecological cancer cell lines was investigated.

METHODS

Semiquantitative reverse transcription polymerase chain reaction analysis was performed to investigate the mRNA expression levels of vascular endothelial growth factors (VEGF-A, -B, -C, and -D), basic fibroblast growth factor (bFGF), and matrix metalloproteinase (MMP)-2 with beta-actin coamplified as an internal standard. Tumor cell migration along a gradient of substratum-bound fibronectin and invasion into reconstituted basement membrane were evaluated by haptotactic migration and invasion assay.

RESULTS

Expression of VEGF-A mRNA was detected in all 16 cell lines, whereas the relative expression levels of other VEGF family members and bFGF, differed markedly among the cell lines. There was a statistical correlation between VEGF-C gene expression and the number of cells that migrated and invaded (P < 0.01). However, expression of mRNAs of other angiogenic factors did not correlate with motility and invasive activity of the cells. Moreover, there was a close correlation between VEGF-C and MMP-2 gene expression levels (P < 0.05).

CONCLUSION

Tumor cells that produce VEGF-C may have a higher invasive and metastatic potential because of their capacity to pass through tissue barriers.

Correlation between thymidine phosphorylase expression and invasion phenotype in cervical carcinoma cells

The correlation between thymidine phosphorylase (dThdPase) expression and invasion phenotype in human uterine cervical carcinoma cells was investigated using 10 cervical carcinoma cell lines. Semi-quantitative reverse transcription-polymerase chain reaction analysis was performed to investigate the mRNA levels of dThdPase and matrix metalloproteinase (MMP)-2 with beta-actin coamplified as an internal standard. dThdPase protein expression levels were detected by highly sensitive enzyme-linked immunosorbent assay. Tumor cell migration along a gradient of substratum-bound fibronectin and invasion into reconstituted basement membrane were evaluated by haptotactic migration and invasion assay. Although dThdPase mRNA and protein expression levels differed remarkably among the cell lines, there was a statistical correlation between them (r = 0.743, p = 0.0139). dThdPase gene and protein expression levels were well correlated with the number of cells that migrated and invaded (p < 0.05). Moreover, there was a close correlation between MMP-2 gene and dThdPase gene and protein expression levels (p < 0.05). Tumor cells that produce dThdPase may have a higher invasive and metastatic potential because of their capacity to pass through tissue barriers.

Tumor angiogenesis as an independent prognostic factor after extended radical esophagectomy for invasive squamous cell carcinoma of the esophagus

BACKGROUND

Currently, there is only limited information regarding tumor angiogenesis and its clinical implications in cases of esophageal carcinoma. The purpose of this study was to clarify which clinicopathologic parameters correlate with tumor angiogenesis; furthermore, the study was conducted to evaluate whether tumor angiogenesis is an independent prognostic factor in cases of esophageal carcinoma.

METHODS

Intratumoral microvessel density (MVD) and thymidine phosphorylase (dThdPase) expression were immunohistochemically studied after extended radical esophagectomy in 103 cases of esophageal carcinoma.

RESULTS

Increased MVD significantly correlated with the depth of tumor invasion, the frequency of intramural metastasis, and the stage of tumor advancement (P <.05). dThdPase expression status significantly correlated with the size and depth of primary tumors (P <.02). A significant correlation was present between MVD and the expression status of dThdPase (P <.01). Furthermore, increased MVD correlated with increased tumor recurrence after esophagectomy and with poorer survival curves (P <.01 and P <.05, respectively). A multivariate analysis revealed MVD to be an independent predictor of unfavorable prognosis.

CONCLUSIONS

Tumor angiogenesis expressed as MVD correlates with clinicopathologic parameters regarding tumor progression and is an independent prognostic indicator in patients undergoing extended radical esophagectomy for invasive esophageal carcinoma.

Tumor angiogenesis and thymidine phosphorylase expression in ovarian carcinomas including serous surface papillary adenocarcinoma of the peritoneum

To clarify biological and clinical significance of tumor angiogenesis in the development of ovarian carcinoma, we investigated the relationship between tumor vascularity, the expression of thymidine phosphorylase (dThdPase), which is an angiogenic factor identical to platelet-derived endothelial cell growth factor (PD-ECGF), and patient outcome in ovarian carcinoma, including serous surface papillary carcinoma (SSPC). Primary tumor specimens (stages I-IV) from 54 patients were examined. Intratumoral microvessel density (IMVD) and dThdPase expression were evaluated immunohistochemically using anti-CD34 and anti-dThdPase antibodies, and results were correlated with clinicopathologic parameters and prognosis. IMVD for the 54 tumors ranged from 22.5 to 120.7 (number/0.73686 mm2/field). Twenty-three tumors were positive, and 31 tumors were negative for dThdPase expression. IMVD positively correlated with the expression of dThdPase (p < 0.01), tumor size, and peritoneal metastases (p < 0.05). However, there was no statistical correlation between IMVD, dThdPase expression, and clinical outcome. Of the 54 patients examined, 30 were diagnosed with International Federation of Gynecology and Obstetrics (FIGO) stage III or IV primary ovarian carcinoma, and 9 were diagnosed with SSPC. There were no significant differences between the two groups with respect to clinicopathologic features, IMVD, dThdPase expression, or patient outcome. In conclusion, angiogenic activity may be necessary for the growth of metastatic implants in ovarian carcinoma and SSPC.