Angiogenic potential of ductal carcinoma in situ (DCIS) of human breast

AIMS: Comedo carcinoma is generally regarded as the subtype of ductal carcinoma in situ (DCIS) most likely to progress to invasive carcinoma. Increased angiogenesis could be associated with an enhanced risk of progression and might therefore be a marker of poor prognosis, as can be demonstrated for invasive breast tumours. Therefore, the present study investigates the correlations between the expression of oncoproteins (HER2, HER1/EGFR), angiogenic growth factors (VEGF and PD-ECGF/TP) and microvessel density (MVD) in DCIS. METHODS AND RESULTS: Forty-six breast cancer specimens of DCIS were tested immunohistochemically for the expression of angiogenic factors and oncoproteins. Different vascular distribution patterns of DCIS were examined semiquantitatively. Our results showed a significantly inverse correlation between HER1/EGFR and comedo-type DCIS (P = 0.048), but HER1/EGFR expression seemed to be independent of HER2 overexpression. VEGF expression was significantly associated with endoglin expression (P = 0.031) and the cuffing phenomenon (P = 0.017). CONCLUSIONS: The significantly inverse correlation between HER1/EGFR and comedo-type DCIS and the observation that VEGF and the other angiogenic factors tested are independent of HER2 overexpression, suggest that progression of comedo-type DCIS and angiogenesis in breast carcinoma are not regulated via the HER1/EGFR or HER2 pathway.     

Macrophage infiltration is associated with VEGF and EGFR expression in breast cancer

Angiogenesis is esential for tumour growth and metastasis. Vascular endothelial growth factor (VEGF) is a potent endothelial cell mitogen and is an important component of the angiogenic stimulus in a range of human neoplasias. In addition to its mitogenic activities, VEGF has also been found to stimulate migration in macrophages via the flt-1 VEGF receptor. It has previously been shown that increased focal tumour macrophage infiltration is associated with increased angiogenesis and worsened relapse-free and overall survival in breast cancer. Macrophages are able to stimulate angiogenesis by their production of a range of factors including VEGF, tumour necrosis factor-alpha (TNF-alpha), and thymidine phosphorylase (TP). Thus, in breast cancer, VEGF could have a dual role in the regulation of angiogenesis, by direct mitogenic stimulation of endothelial cells, and also indirectly by attracting macrophages into avascular tumours. The purpose of this study was to localize VEGF protein in a series of 96 consecutive primary breast carcinomas and to determine its relationship to focal macrophage infiltration (macrophage index). These two variables were also compared with the pathological features of the tumours, as well as oestrogen receptor (ER), epidermal growth factor receptor (EGFR), microvessel density, macrophage index, and survival. An inverse relationship (p=0.0006) was noted between VEGF and EGFR, with high VEGF expression correlating with low EGFR levels. In the EGFR-negative group of cases (n=56), positive associations were observed between VEGF expression and macrophage index (p=0.005), ER (p=0.05), p53 (p=0. 006), tumour grade (p=0.02), and tumour necrosis (p=0.03). Macrophage counts were higher in EGFR-positive tumours (p=0.0006) and no associations were found between VEGF expression and increased microvessel density. These results show that in breast cancers there are two types of macrophage infiltrates, one associated with the presence of EGFR and low VEGF expression in tumours and the other with high VEGF expression in EGFR-negative tumours. VEGF expression may be an important factor in the recruitment of tumour-associated macrophages into breast carcinomas and may thus have an additional, indirect, pathway of angiogenic stimulation in this type of tumour.     

Platelet-derived endothelial cell growth factor expression and angiogenesis in cervical intraepithelial neoplasia and squamous cell carcinoma of the cervix

Growth and metastatic spread of invasive carcinoma depends on angiogenesis, the formation of new blood vessels. Platelet-derived endothelial cell growth factor (PD-ECGF) is an angiogenic growth factor for a number of solid tumors, including lung, bladder, colorectal, and renal cell cancer. Cervical intraepithelial neoplasia (CIN) is the precursor to squamous cell cervical carcinoma (SCC). Mean vessel density (MVD) increases from normal cervical tissue, through low- and high-grade CIN to SCC. We evaluated PD-ECGF immunoreactivity and correlated its expression with MVD in normal, premalignant, and malignant cervical tissue. PD-ECGF expression was assessed visually within the epithelial tissues and scored on the extent and intensity of staining. MVD was calculated by counting the number of vessels positive for von Willebrand factor per unit area subtending normal or CIN epithelium or within tumor hotspots for SCC. Cytoplasmic and/or nuclear PD-ECGF immunoreactivity was seen in normal epithelium. PD-ECGF expression significantly increased with histologic grade from normal, through low- and high-grade CIN, to SCC (P < .02). A progressive significant increase in the microvessel density was also seen, ranging from a mean of 28 vessels for normal tissue to 57 for SCC (P < .0005). No correlation was found between PD-ECGF expression and MVD (P = .45). We conclude that PD-ECGF expression and MVD increase as the cervix transforms from a normal to a malignant phenotype. PD-ECGF is thymidine phosphorylase, a key enzyme in the activation of fluoropyrimidines, including 5-fluorouracil. Evaluation of PD-ECGF thymidine phosphorylase expression may be important in designing future chemotherapeutic trials in cervical cancer.     

Expression of angiogenic factors and apoptotic factors in leiomyosarcoma and leiomyoma.

Angiogenesis is essential for tumor growth and metastasis. Some angiogenic factors, such as vascular endothelial growth factor (VEGF), platelet-derived endothelial cell growth factor (PD-ECGF), transforming growth factor-alpha (TGF-alpha) and basic fibroblast growth factor (bFGF) are involved in increased angiogenic activity and disease progression in many carcinomas. However, there is little information regarding the association between angiogenic factors and leiomyosarcoma. Although there are abundant vessels in the sarcoma which enable it to easily receive nutrition and medicinal components, chemotherapy cannot effectively treat leiomyosarcoma. This means the resistance to anticancer drugs in leiomyosarcoma is very strong. However, the resistant mechanism is still unclear. In this study, expressions of VEGF, PD-ECGF, TGF-alpha, bFGF, intratumoral microvessel density (IMVD), and p53, Bcl-2 and Bax were examined by immunohistochemistry in 30 patients with leiomyosarcoma and 21 patients with leiomyoma. With regard to angiogenesis, PD-ECGF and TGF-alpha were closely associated with an increase in IMVD (p=0.012, 0.0196, respectively), and VEGF and PD-ECGF were significantly expressed in leiomyosarcoma compared with leiomyoma (p=0.041, 0.041, respectively). Although p53 expression in leiomyosarcoma was significantly higher than in leiomyoma (p=0.016), the frequency of p53 positivity was not so high (47%). On the other hand, the ratio of Bcl-2/Bax in leiomyosarcoma was significantly higher than that in leiomyoma (p=0.033). The findings of this study suggest that in leiomyosarcoma, angiogenic factors, such as PD-ECGF, VEGF and TGF-alpha expression may be involved in tumor angiogenesis, and the frequently high ratio of Bcl-2/Bax and expression of p53 gene mutation might be related to chemoresistance mechanism.     

Correlation between vascular endothelial growth factor,angiogenesis, and tumor-associated macrophages in invasive ductal breast carcinoma

Angiogenic and anti-angiogenic factors, secreted by tumor, inflammatory, and stromal cells play an important role in regulation of neovascularization. Among the most important of these is vascular endothelial growth factor (VEGF), a specific mitogen for endothelium, which increases vascular permeability and induces proteolytic enzymes necessary for vascular remodeling. Tumor-associated macrophages (TAMs) can express complex functions related to tumor biology, including growth, proliferative rate, stroma formation and dissolution, and neovascularization. The aim of this study was to define, using immunohistochemical analysis, the microvessel density (MVD), VEGF expression, and TAMs level in 97 human invasive ductal breast carcinomas not otherwise specified (NOS), investigate a possible relationship between them and then correlate their values with tumor grade, mitotic activity index (MAI), tumor size and lymph-node status. Statistical analysis showed a strong positive relationship between MVD and VEGF expression ( P<0.001). Furthermore, both MVD and VEGF expression were significantly correlated with tumor grade and lymph-node status, and TAMs infiltration with MAI. TAM level showed a significant positive connection with VEGF expression and MVD. These in situ observations suggest that VEGF stimulates angiogenesis in human invasive ductal breast carcinoma NOS and attracts macrophages to the tumor locus, which then may be involved in angiogenesis promotion. The expression of this angiogenic molecule, and MVD and TAM level, can provide additional prognostic significance and help in the identification of patients who need postoperative adjuvant therapy.     

Prognostic significance of angiogenesis in gastrointestinal stromal tumor.

Angiogenesis is important in the growth and metastasis of various kinds of solid tumors. To investigate the potential role of angiogenesis in gastrointestinal stromal tumor (GIST), an immunohistochemical analysis was performed in 95 cases of GISTs for microvessel density (MVD) and vascular endothelial growth factor (VEGF) expression. MVD was evaluated with immunohistochemical staining for CD31. A high level of MVD was significantly correlated with overexpression of VEGF, tumor location (intestine>stomach), tumor size (> or =5 cm), tumor grade (high>intermediate>low grade) (P=<0.0001, 0.0422, 0.0006, 0.0359, respectively). Of the 70 GISTs analyzed, KIT exon 11 mutations were detected in 45 cases (64.3%) and KIT exon 9 mutations in two cases (2.9%). No mutations were found in KIT exons 13 and 17, and platelet-derived growth factor receptor-alpha exons 12 and 18. Interestingly, VEGF expression level was significantly higher in the non-KIT exon 11 mutant group than in the KIT exon 11 mutant group (P=0.0266). In univariate analysis, tumor grade (high grade), tumor size (> or =5 cm), mitotic count (> or =5/50 high-power fields), Ki-67 labeling index (> or =4.6%), MVD (> or =7.0/0.95 mm(2)) and VEGF expression (high) were significantly associated with a shorter period of disease-free survival (P=<0.0001, 0.0199, 0.0055 0.0027, 0.0028 and 0.0302, respectively). In multivariate analysis, tumor grade and MVD were identified as independent worse prognostic factors (P=0.0007, 0.0152, respectively). In conclusion, our results suggest that the evaluation of MVD and VEGF expression is useful for predicting the aggressive biologic behavior of GIST, and that angiogenesis associated with VEGF may play an important role, at least in part, in the progression of GIST.     

Correlation of epidermal growth factor receptor expression with tumor microdensity vessels and with vascular endothelial growth factor expression in ovarian carcinoma

We analyzed in advanced ovarian serous G3 carcinoma the correlation between epidermal growth factor receptor (EGFR) overexpression and tumor angiogenesis and their relation with clinical outcome. Microvessel density (MVD) and vascular endothelial growth factor (VEGF) were statistically correlated with disease-free interval and death from disease both in univariate and multivariate analyses while EGFR expression was not correlated with clinical outcome. MVD was significantly associated with progression of disease during chemotherapy while VEGF and EGFR expression were not correlated with responsiveness to chemotherapy (Fisher's exact test). VEGF expression was correlated with MVD (Fisher's exact test). EGFR showed a trend to correlation with MVD. Further studies focusing on the use of angiogenesis inhibitors in addition to EGFR inhibitors on ovarian carcinoma cells may produce therapeutic strategies in the selection of tailored therapies in ovarian cancer patients.     

Growth index is independent of microvessel density in non-small-cell lung carcinomas

Induction of angiogenesis is essential for carcinogenesis and facilitates the processes of tumor development and metastasis. Vascular endothelial growth factor (VEGF) is an important angiogenic regulator under physiologic and pathologic conditions. To elucidate the role of angiogenesis in malignant growth, we evaluated angiogenesis and VEGF expression in a panel of 68 non-small-cell lung carcinomas (NSCLCs) and examined their relation with the kinetic parameters, ploidy, and p53 protein status, which have been analyzed previously. Angiogenesis was estimated as microvascular density (MVD) of the tumor area by CD31 immunodetection. Expression of VEGF was also immunohistochemically evaluated. All possible associations were assessed through a series of statistical methods. The mean MVD value was 39 microvessels/mm(2), and high VEGF immunoreactivity was observed in all specimens, with a mean percentage of positive cells of 73%. The relation between MVD and VEGF expression was not statistically significant (P = 0.065). No association was observed between MVD or VEGF levels with the proliferation index, apoptotic index, tumor ploidy status, p53 expression, and overall survival. We conclude that in a subset of NSCLCs, angiogenesis may be associated with VEGF, but other factors also participate in this process. Angiogenesis and growth (proliferation and apoptosis) are independent and probably differentially operated procedures, with only growth partially controlled by p53 protein expression.     

乳腺癌组织Livin和PTEN表达与肿瘤血管生成的相关性

目的:研究乳腺癌组织中凋亡抑制蛋白Livin和抑癌基因PTEN的表达与微血管密度(MVD)的关系,探讨乳腺癌血管生成的影响机制。方法:应用免疫组化Elivision法检测90例乳腺癌和30例乳腺纤维腺瘤组织中Livin、PTEN、VEGF的表达和CD34标记的MVD值,分析Livin和PTEN表达与乳腺癌血管生成及侵袭转移的关系。结果:在90例乳腺癌中Livin、PTEN和VEGF表达阳性率分别为54.4%、48.9%和61.1%,MVD为(30.81±11.29)个/HPF,与良性对照组比较均有显著差异(P<0.01);Livin阳性表达与乳腺癌肿瘤大小、临床分期、MVD值及VEGF表达呈正相关(P<0.05),与年龄、病理分级、淋巴结转移未见显著相关(P>0.05);PTEN表达与乳腺癌淋巴结转移、临床分期和MVD呈负相关(P<0.05),与VEGF表达、年龄、肿瘤大小、病理分级未见显著相关(P>0.05)。结论:Livin和PTEN在乳腺癌的血管生成及发生发展过程中分别起促进和抑制作用,Livin的促血管生成作用可能与其上调VEGF的表达有关。     

Review: molecular pathology of cyclooxygenase-2 in cancer-induced angiogenesis.

Cancer-induced angiogenesis is the result of increased expression of angiogenic factors, or decreased expression of anti-angiogenic factors, or a combination of both events. For instance, in colon cancer, the malignant cells, the stromal fibroblasts, and the endothelial cells all exhibit strong staining for cyclooxygenase-2 (COX-2), the rate-controlling enzyme in prostaglandin (PG) synthesis. In various cancer tissues, vascular endothelial growth factor (VEGF) and transforming growth factor beta (TGF-beta) co-localize with COX-2. Strong COX-2 and VEGF expression is highly correlated with increased tumor microvascular density (MCD); new vessels proliferate in areas of the tumor that express COX-2. Moreover, high MVD is a predictor of poor prognosis in breast and cervical cancers. COX-2 and VEGF expression are elevated in breast and prostate cancer tissues and their cell-lines. In vitro, PGE2 induces VEGE Supernatants of cultured cells from breast, prostate, and squamous cell cancers contain angiogenic proteins such as COX-2 and VEGF that induce in vitro angiogenesis. A selective COX-2 inhibitor, NS-398, restores tumor cell apoptosis, reduces microvascular density, and reduces tumor growth of PC-3 prostate carcinoma cells xenografted into nude mice. The COX-2 produced by a malignant tumor and COX-2 produced by the surrounding host tissue both contribute to new vessel formation, which explains how selective COX-2 inhibition reduces tumor growth where the tumor COX-2 gene has been silenced by methylation.     

Inactivation of the PTEN gene protein product is associated with the invasiveness and metastasis, but not angiogenesis, of breast cancer

PTEN is a novel tumor-suppressor gene located on chromosomal band 10q23. Loss of PTEN function has been implicated in the progression of several types of cancer, but the correlation between loss of PTEN expression and advanced carcinomas is not well established. The capacity for angiogenesis of a tumor is known to play a very important role in growth and metastasis, and there have been reports that PTEN relates to angiogenesis. In the present study, formalin-fixed and paraffin embedded tissues from 101 patients with breast carcinomas, including 88 cases of invasive ductal carcinomas and 13 cases of ductal carcinoma in situ (DCIS), were evaluated by immunohistochemical methods for the expression of PTEN and vascular endothelial growth factor (VEGF), as well as microvessel density (MVD). The results were compared with the clinicopathologic parameters. There was no loss of PTEN expression in any of the cases of DCIS, but 28 (32%) of the 88 invasive cases did not express PTEN. Loss of PTEN expression was associated with lymph node metastasis ( P  = 0.03), but did not correlate with tumor size, tumor grade, MVD or recurrence. VEGF expression significantly correlated with lymph node metastasis in invasive ductal carcinoma ( P  = 0.01). There was no correlation between the expression of PTEN and that of VEGF ( P  = 0.63). The present study suggests that loss of PTEN expression is common and correlates with tumor progression and lymph node metastasis in breast carcinoma. The relationship between loss of PTEN and progression of breast cancer may not be explained by modulation of angiogenesis.     

Angiogenic co-operation of VEGF and stromal cell TP in endometrial carcinomas

Vascular endothelial growth factor (VEGF) and thymidine phosphorylase (TP) are important angiogenic enzymes, inducing new blood vessel formation in many human malignancies. In this study, the immunohistochemical expression of the two molecules was analysed in a series of 121 endometrial carcinomas. VEGF was expressed exclusively in cancer cells, while TP expression was shown in cancer cells (TPcc) and in stromal cells (TPsc) of both fibroblastic and myometrial origin. In all cases, enzymatic detection was particularly evident at the invading tumour front. At this site, TPsc, but not VEGF, expression was associated with non-endometrioid-type carcinomas, high tumour grade, deep myometrial invasion, and advanced stage. VEGF, but not TP, expression was related to increased angiogenesis (p=0.01). Double stratification of the two factors, however, marked VEGF/TPsc co-expression as the most potent angiogenic phenotype (p=0.008), suggesting a synergistic function. Survival analysis revealed that VEGF and TPsc, whether expressed alone or in combination, define poor prognosis. In multivariate analysis, however, stage of disease (p<0.0001, t-ratio 4.4) and VEGF expression (p=0.01, t-ratio 2.4) were the most important prognostic variables. Furthermore, VEGF expression emerged as the only independent prognostic variable in stage I endometrial carcinomas (p=0.04, t-ratio 1.9). This was not shown for TP, probably because of its close association with histopathological parameters. In conclusion, VEGF is a major angiogenic factor in endometrial carcinomas and an independent prognostic factor in stage I endometrial disease. TP is not an effective contributor to the angiogenic process, but is associated with aggressive histological features. The two factors, when co-expressed, play a co-operative role in the induction of angiogenesis.     

Expression of EGFR and c-kit is associated with the basal-like phenotype in breast carcinomas of African women

Epidermal growth factor receptor (EGFR) and c-kit are tyrosine kinase growth factor receptors which are frequently expressed in basal-like breast carcinomas, and tyrosine kinase inhibition is now a promising strategy in treatment of breast cancer. The aim of this study was to evaluate the expression of EGFR and c-kit in breast cancer with special focus on the basal-like phenotype (BLP) and other prognostic factors in an African population. We analyzed 65 archival tissues immunohistologically. EGFR and/or c-kit were expressed in 55% of basal-like tumors. Expression of EGFR and/or c-kit was strongly associated with high histologic grade (P=0.001), high nuclear grade (P=0.017), high mitotic counts (P=0.002), ER negativity (P=0.003), PR negativity (P=0.007), and HER2 negativity (P=0.014). EGFR and/or c-kit positive tumors were more likely to express the BLP (OR 9.1, CI 2.6-32.0, P<0.0005) than the negative tumors. In conclusion, there is a high expression of EGFR and/or c-kit in basal-like breast carcinoma in this series from Uganda and their expression is associated with features of poor prognosis. More studies are required to assess the clinical significance of EGFR and c-kit in breast cancer patients in Uganda.     

Angiopoietins 1 and 2 and Tie-2 receptor expression in human ductal breast disease

Staton C A, Hoh L, Baldwin A, Shaw L, Globe J, Cross S S, Reed M W & Brown N J
(2011) Histopathology 59 , 256–263 Angiopoietins 1 and 2 and Tie‐2 receptor expression in human ductal breast disease Aims: This study aimed to identify the involvement of the angiopoietin/Tie‐2 receptor system in breast cancer development, progression, metastasis and angiogenesis. Methods and results: We quantified and correlated angiopoietin‐1 (Ang‐1), Ang‐2 and Tie‐2 expression in sections of normal human breast, benign and premalignant hyperplastic tissue, pre‐invasive and invasive cancer, and compared these findings with our previously published data on vascular endothelial growth factor (VEGF) and microvessel density (MVD) in the same samples. A breast cancer tissue microarray was used to evaluate the prognostic value of these factors. Histological analysis revealed a significant decrease in Ang‐1 expression (P = 0.001) and an inverse correlation with MVD (r = ?0.442, P = 0.008) and VEGF (r = ?0.510, P = 0.002) in the non‐invasive lesions. In contrast Ang‐2 expression increased significantly (P = 0.0004) with increasing severity of lesion and correlated with MVD (r = 0.570; P = 0.0002), while Tie‐2 expression remained relatively unchanged. Expression of all three factors was reduced in invasive breast cancer and did not correlate with oestrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2), lymph node status or tumour grade. Conclusions: These data suggest that a change in the angiopoietin balance in favour of Ang‐2 is associated with the angiogenic switch at the onset of hyperplasia in the breast. However, angiopoietins and the Tie‐2 receptor are not related to known prognostic indicators in invasive breast cancer.     

Tissue factor expression and angiogenesis in human prostate carcinoma

In tumors, the switch to the angiogenic phenotype is thought to be controlled by a balance of positive and negative angiogenic factors. Tissue factor (TF) produced by tumor cells has been implicated in the regulation of this "angiogenic switch" through its ability to concurrently induce the expression of angiogenic molecules such as vascular endothelial cell growth factor (VEGF), while inhibiting the expression of anti-angiogenic molecules such as thrombospondin 2. We have examined TF expression and its relationship to angiogenesis and tumor progression in human prostate carcinomas. Most of the prostate carcinoma specimens examined (73%; n = 67) express high levels of TF. Immunohistochemical analysis localized TF expression to the epithelial cells of malignant glands. TF expression was significantly correlated with tumor angiogenesis as measured by the microvessel density (MVD). In addition, TF expression was correlated with the preoperative PSA level, a strong predictor of recurrence in prostate carcinomas. Our findings show that TF expression by the malignant glands in prostate cancer is common and suggest a role for this molecule in regulating prostate cancer progression and angiogenesis.     

HIF-2α、VEGF、COX-2、MMP-9表达及其与肾细胞癌血管生成的关系分析

目的 探讨HIF-2α(缺氧诱导因子-20α)、VEGF(血管内皮生长因子)、COX-2(环氧化酶-2)、MMP-9(金属基质酶-9)表达及其与肾细胞癌血管生成的关系.方法 应用免疫组化方法,检测79例肾细胞癌手术切除标本的HIF-2α、VEGF、COX-2、MMP-9表达情况,并与MVD(微血管密度)表达进行关联性分析.结果 肾癌组织MMP-9、VEGF的表达均显著高于正常肾组织(P＜0.05);不同临床分期肾癌组织中的MMP-9、VEGF表达有明显差异(P＜0.05).MVD与VEGF、MMP-9蛋白表达呈显著正相关(r=0.381、0.375,P＜0.05);MVD与COX-2表达有关,COX-Z表达0级和4级MVD值最低,与1、2、3级之间比较差异有统计学意义(P＜0.05),0级与4级之间比较差异无统计学意义(P＞0.05),1、2、3级之间差别无统计学意义(P＞0.05).肾细胞癌中HIF-2α阳性组的MVD值高于HIF-2α阴性组中MVD值,差异有统计学意义(t=4.374,P＜0.05);Spearman等级相关分析发现,HIF-2α的表达与MVD间存在正相关关系(r=0.545,P＜0.01).结论 HIF-2α、VEGF、COX-2、MMP-9表达及其与肾细胞癌血管生成之间有明显相关性,在临床上可以根据相关基因表达情况而采取相应的干预措施.     

Platelet-derived endothelial cell growth factor/thymidine phosphorylase expression in normal tissues: An immunohistochemical study

Angiogenesis is the formation of new blood vessels from the existing vascular bed. It is a complex multi-step process controlled by a number of angiogenic factors. One such factor is platelet-derived endothelial cell growth factor (PD-ECGF), recently shown to be thymidine phosphorylase (TP), which is angiogenic in several in vivo assays and tumour systems. PD-ECGF/TP catalyes the reversible phosphorylation of thymidine to deoxyribose-1- phosphate and thymine. Since PD-ECGF/TP has an important role in cellular metabolism and in angiogenesis and its expression has been only partially characterized, we raised a monoclonal antibody against recombinant PD-ECGF/TP and used an immunohistochemical approach to examine the expression of PD-ECGF/TP in a comprehensive range of normal human tissues. The clone P-GF44. C, which recognized recombinant PD-ECGF-TP and cell lysates transfected with a plasmid expressing PD-ECGF/TP cDNA on Western blotting, was selected for its ability to stain routinely processed tissue. Staining was observed in both the cytoplasm and/or the nucleus. Immunoreactivity was strongly expressed by macrophages, stromal cells, glial cells, and some epithelia. Gastrointestinal epithelium, smooth muscle, adrenal, lung, and testis were negative. Although endothelial cell expression was observed, there was no correlation with sites of new vessel growth. This pattern of expression suggests tight PD-ECGF/TP regulation and that cellular thymidine pools may serve to control its different functions. Thus, in the nucleus it might modulate the pool for DNA synthesis, whilst in the cytoplasm it could control other effects through different enzyme systems. The high expression present in macrophages and skin might be important for total body thymidine homeostasis.     

Thymidine phosphorylase expression in gallbladder adenocarcinomas

The expression of thymidine phosphorylase (TP), a potent chemotactic factor for endothelial cells, was studied in 60 adenocarcinomas of the gallbladder, by use of immunohistochemical techniques. Results on patterns of TP expression were correlated with angiogenesis (anti-CD31), histopathological variables, and patient survival. TP was frequently expressed in tumor cells, stromal cells, tumor-associated macrophages, and lymphocytes of gallbladder adenocarcinomas. The expression was mixed nuclear/cytoplasmic. However, only nuclear TP (TPnuc) expression by tumor cells was correlated with increased angiogenic activity. High angiogenesis, assessed as microvessel density (MVD), was the most significant prognostic factor. The subgroup of patients with TPnuc and medium/high MVD had the worst prognosis as evaluated by the survival curves. Furthermore, CD31+ lymphocytes, frequently seen in carcinomas with high-fibroblastic TP reactivity, were connected with an improved survival. It is concluded that angiogenesis, as verified by multivariate analysis, is the most important prognostic factor in gallbladder carcinomas. In these tumors, high histologic grade and low CD31+ lymphocytic infiltration are also independent predictors of poor prognosis. TP is associated with an aggressive phenotype apparently because of its anglogenic activity. Therapeutic strategies targeting TP may be of value in patients overexpressing this enzyme.