Autophagy and hypoxia in colonic adenomas related to aggressive features

AIM

The study investigated whether autophagic activity and hypoxia parallel the adenoma-carcinoma sequence.

METHOD

The study comprised 120 tubular adenomas with high-grade dysplasia, including 22 with questionable evidence of invasion, 37 with definite stromal invasion and 29 with severely dysplastic adenoma, 10 traditional serrated adenomas and 22 classical tubular adenomas lacking aggressive features. The samples were stained immunohistochemically for autophagy (LC3A and Beclin-1) and hypoxia-inducible factor1-alpha (HIF1α) markers.

RESULTS

LC3A was detected as diffuse cytoplasmic staining and as dense "stone-like" structures (SLS) within cytoplasmic vacuoles. Beclin-1 reactivity was purely cytoplasmic, whereas that of HIF1α was both cytoplasmic and nuclear. SLS counts in noninvasive, nontransformed areas of tubular adenomas were consistently low (median SLS = 0.5; 200× magnification), whereas a progressive increase was noted from areas of equivocal invasion (median SLS = 1.3; 200× magnification) and intramucosal carcinoma (median SLS = 1.4; 200× magnification) to unequivocal invasive foci (median SLS = 2.1; 200× magnification) (P < 0.0001). A similar association was shown for Beclin-1 and HIF1α expression (P < 0.05). Traditional serrated adenomas yielded low SLS counts and weak HIF1α reactivity, but high cytoplasmic LC3A and Beclin-1 expression (P < 0.01).

CONCLUSION

A hypoxia-driven autophagy in adenomatous polyps, when particularly intense and localized, is commonly associated with early invasion or severely dysplastic adenoma.

p53 Overexpression in laryngeal squamous cell carcinoma and dysplasia

Aim-To investigate the expression of p53 protein in invasive squamous cell carcinoma (SCC) of the larynx and dysplasia in relation to histological grade and tobacco smoking.Method-Paraffin wax embedded tissue sections from 41 cases of invasive SCC of the larynx, 28 cases of dysplasia and 14 control laryngeal biopsy specimens were studied immunohistochemically using two anti-p53 monoclonal antibodies (DO7 and 1801). The Streptavidin/horseradish peroxidase method was used after microwave antigen retrieval and a semiquantitative method was applied to assess the extent of p53 expression.Results-Of the cases of invasive SCC of the larynx, 78% (32/41), regardless of histological grade, overexpressed p53 compared with only 30% (eight of 28) of cases of mild dysplasia. A gradual increase in p53 expression from mild to severe dysplasia (60%) was observed, and only three of 14 control biopsy specimens of laryngeal nodules showed occasional weakly positive basal cells.Conclusion-The gradual increase in p53 expression from mild to severe dysplasia to invasive SCC indicates that p53 overexpression is an early event in laryngeal carcinogenesis which may lead to invasive malignancy. p53 overexpression may be related to environmental factors as most of the patients smoked tobacco. Microwave postfixation may be essential for the reliable detection of p53.

Activated VEGFR2/KDR pathway in tumour cells and tumour associated vessels of colorectal cancer

BACKGROUND

Vascular endothelial cell growth factor (VEGF) acts by phosphorylating specific tyrosine kinase receptors on endothelial cell membrane promoting angiogenesis. The study of the activation status of VEGF receptors in human malignancies has recently become feasible by means of specific monoclonal antibodies recognising the phosphorylated form of these receptors.

MATERIALS AND METHODS

In the current study, we investigate the expression of the phosphorylated VEGFR2/KDR receptor in normal colon and colorectal adenocarcinomas in parallel with histopathological parameters, prognosis and the expression of the 'hypoxia inducible factor' HIF1alpha.

RESULTS

pVEGFR2/KDR was weakly expressed in the normal colon, but it was expressed strongly in the cytoplasm and nuclei of cancer cells and in the tumour associated vasculature, mainly at the invading tumour edge. pVEGFR2/KDR expression in cancer cells was significantly associated with a tumour diameter > 6 cm (P = 0.04), poor histological differentiation (P = 0.004) and with high CEF1alpha expression (P = 0.05). High pVEGFR2/KDR expressing vascular density was significantly related with a high VEGF and HIF1alpha expression in cancer cells (P = 0.02 and 0.03, respectively). This was also related significantly to high pVEGFR2/KDR expression in cancer cells. In multivariate analysis, the most significant predictors for death were lympho-vascular invasion (P < 0.001) followed by VEGF (P = 0.014), node status (P = 0.015), standard vascular density (P = 0.022) and necrosis (P = 0.032).

CONCLUSIONS

pVEGFR2 receptors are largely expressed in colon cancer cells and intratumoural vasculature. As VEGF targeting agents enter the clinical practice, the role of monoclonal antibodies recognising the phosphorylated form of VEGF receptors as predictors of response to targeted therapies should be sought in clinicopathological trials.

Plasmablastic lymphomas may occur as post-transplant lymphoproliferative disorders

AIMS

To describe four cases of plasmablastic lymphoma arising in the unusual setting of a post-transplantation lymphoproliferative disorder (PTLD).

METHODS AND RESULTS

Four cases were encountered over 2 years in human immunodeficiency virus (HIV)-negative patients following renal, heart or bone marrow transplantation. The cases were routinely processed and immunohistochemistry was performed. The cases showed blastic non-Hodgkin's lymphoma morphology and plasma cell-like immunophenotypic features: minimal or absent expression of leucocyte common antigen and CD20, variable CD79a and VS38 positivity. Monoclonal light chain restriction was also detected.

CONCLUSIONS

The emphasis of this paper is to document further the occurrence of plasmablastic lymphomas in HIV- individuals and to expand the spectrum of PTLD.

Prognostic significance of microvessel density and other variables in Japanese and British patients with primary invasive breast cancer

The purpose of this study is to investigate the associations of microvessel density (MVD) and other pathological variables with survival, and whether they accounted for survival differences between Japanese and British patients. One hundred seventy-three Japanese and 184 British patients were included in the study. British patients were significantly older (56.3±11.4 years vs 52.5±12.9 years; P<0.01) and had smaller tumours (2.2±1.3 vs 2.7±1.8 cm; P<0.01), which were more frequently oestrogen receptor positive (78.8 vs 57.2%, P<0.01), had more grade III tumours (29.9 vs 21.4%, P=0.04) and more infiltrating lobular carcinomas (13.6 vs 4.0%, P<0.01) and a higher MVD compared with Japanese patients (57.9±19.8 vs 53.2±18.6; P=0.01). However, no difference in the prevalence of lymph-node metastasis was found between them (39.1 vs 37.5%, P=0.75). Younger British patients (age <50 years) had the highest MVD compared with Japanese and older British patients (P<0.01). Japanese patients were proportionately more likely to receive chemotherapy than endocrine therapy (P<0.01). British patients had a significantly worse relapse-free survival and overall survival compared with Japanese patients, after statistical adjustment for variables (hazard ratio=2.1, 2.4, P<0.01, P<0.01, respectively), especially, in T2 stage, low MVD and older subgroup (HR: 3.6, 5.0; 3.1, 3.3; 3.2, 3.9, respectively), but only in ER negative cases (P=0.04, P=0.01, respectively). The present study shows that MVD contributes to the Japanese–British disparity in breast cancer. However, the MVD variability did not explain the survival differences between Japanese and British patients.

Intratumoral lactate dehydrogenase 5 (LDH5) protein expression is associated with expression of angiogenesis markers and hypoxia in patients with colorectal cancer (CRC)

4107

Background: Recent clinical trials (CONFIRM 1 and CONFIRM 2) have shown that metastatic CRC patients (pts) with high serum lactate dehydrogenase (LDH) derive the greatest therapeutic benefit from PTK787/ZK 222584 (PTK/ZK). PTK/ZK is a novel, oral tyrosine kinase inhibitor (TKI), which blocks all known VEGF receptors (VEGFR). From previous studies, total LDH and isoenzyme LDH5 have been associated with tumor aggressiveness and hypoxia. In the present study, we tested whether CRC pts with high levels of tumor LDH5 have increased expression of proteins involved with hypoxia (hypoxia inducible factors [HIF1a and 2a], pyruvate dehydrokinase [PDHK]), increased vessel density (VD), angiogenesis (VEGFA; phosphorylated VEGFR2 [pKDR]), acidity (carbonic anhydrase 9 [CA9]), and others. Methods: Baseline sections from either primary or metastatic tumor sites from 42 pts of the CONFIRM 1 and 2 trials were analysed with immunohistochemistry utilizing an established nominal scoring system. The degree of association between the scores of protein expressed was estimated by the phi-coefficient (correlation coefficient) and assessed by means of p-values from pairwise Fisher’s exact test (two- sided). Results: Associations were observed between LDH5 and the following: pKDR (Phi=.53; p<.001), VEGF (Phi=.41; p=.006), HIF-1a (Phi=.56; p<.001), VD (Phi=.34; p=.052), and PDHK (Phi=.58; p=.014), respectively. HIF-1a associated with pKDR (Phi=.38; p=.027), VD (Phi=.34; p=.045), and VEGFA (Phi=.33; p=.067). VEGFA associated with PDHK (Phi=.52; p=.035). Conclusions: Our results demonstrate that mCRC patients with high level of intratumoral protein expression of LDH5 have elevated HIF-1a, pKDR, VEGFA, PDHK expression and VD. These results support the concept that tumor hypoxia and angiogenesis are associated and that elevated LDH protein expression may serve as a surrogate marker for activated HIF-1a pathway.

No significant financial relationships to disclose.

BNIP3 expression in endometrial cancer relates to active hypoxia inducible factor 1alpha pathway and prognosis

AIMS

BNIP3 is a pro-apoptotic mitochondrial protein induced under hypoxic stress, with the BNIP3 gene being under direct regulation of the hypoxia-inducible HIF-1alpha transcription factor. Induction of BNIP3 leads to caspase-independent necrosis-like cell death and an aggressive tumour phenotype. The role of BNIP3 in endometrial cancer was examined.

METHODS

The immunohistochemical patterns of BNIP3 expression in 72 early endometrial adenocarcinomas of the endometrioid cell type were studied. Correlation of BNIP3 with the hypoxia-inducible factor HIF-1alpha pathway and with prognosis was also examined.

RESULTS

BNIP3 was strongly and extensively expressed in the cytoplasm of cancer cells in 23/72 (31.9%) cases. This high BNIP3 reactivity was not related to histological grade, depth of myometrial invasion or steroid hormone receptor expression. There was, however, a significant association of BNIP3 reactivity with HIF-1alpha (p = 0.04), VEGF (p = 0.04) and, particularly, LDH-5 expression (p = 0.0001). Furthermore, high BNIP3 was associated with poor survival in both univariate (p = 0.05) and multivariate (p = 0.03) models.

CONCLUSION

BNIP3 seems to be an important hypoxia-regulated molecule involved in endometrial cancer pathology. Given that high BNIP3 reactivity, being linked with poor post-operative outcome, has been linked with a favourable response to cytotoxic therapy (as previously indicated in experimental studies), high BNIP3 expression may be an indicator for adjuvant chemoradiotherapy in stage I endometrial carcinomas.

BNIP3 expression in follicular lymphoma

AIMS

To investigate the role of BNIP3, a 19-kDa interacting protein of the Bcl-2 family, alongside Bcl-2 in follicular lymphoma in comparison with reactive lymphoid hyperplasia. The results were compared with those from p53 and caspase-3 (apoptotic markers) and Ki67 (proliferation marker).

METHODS AND RESULTS

Immunohistochemistry using monoclonal antibodies showed BNIP3 to be strongly expressed in most follicular lymphomas but to be weak to negative in all of the reactive cases. There was also an inverse relationship with Bcl-2 expression. There was no correlation of BNIP3 immunoreactivity with proliferation and caspase and p53 were virtually negative in all follicular lymphomas and reactive lymphoid cases.

CONCLUSIONS

BNIP3 is strongly expressed in most follicular lymphomas, especially those that are Bcl-2 negative. BNIP3 may serve as a marker of more aggressive behaviour in follicular lymphoma and be useful diagnostically in the distinction from reactive lymphadenitis.

CD70 (TNFSF7) is expressed at high prevalence in renal cell carcinomas and is rapidly internalised on antibody binding

In order to identify potential markers of renal cancer, the plasma membrane protein content of renal cell carcinoma (RCC)-derived cell lines was annotated using a proteomics process. One unusual protein identified at high levels in A498 and 786-O cells was CD70 (TNFSF7), a type II transmembrane receptor normally expressed on a subset of B, T and NK cells, where it plays a costimulatory role in immune cell activation. Immunohistochemical analysis of CD70 expression in multiple carcinoma types demonstrated strong CD70 staining in RCC tissues. Metastatic tissues from eight of 11 patients with clear cell RCC were positive for CD70 expression. Immunocytochemical analysis demonstrated that binding of an anti-CD70 antibody to CD70 endogenously expressed on the surface of A498 and 786-O cell lines resulted in the rapid internalisation of the antibody-receptor complex. Coincubation of the internalising anti-CD70 antibody with a saporin-conjugated secondary antibody before addition to A498 cells resulted in 50% cell killing. These data indicate that CD70 represents a potential target antigen for toxin-conjugated therapeutic antibody treatment of RCC.

Hypoxia inducible factors 1alpha and 2alpha are associated with VEGF expression and angiogenesis in gallbladder carcinomas

AIMS

To investigate the significance of the hypoxia inducible factors HIF-1alpha and HIF-2alpha in gallbladder adenocarcinomas and their relation to angiogenesis and to the expression of VEGF, an angiogenic factor transcriptionally regulated by HIFalphas.

METHODS

HIF-1alpha and 2alpha expression was assessed immunohistochemically in 60 patients with early gallbladder adenocarcinomas, treated with surgery alone. In addition, the vascular density (VD) and the expression of the angiogenic factors VEGF and thymidine phosphorylase (TP) were examined. The results were correlated with clinico-pathological features and prognosis.

RESULTS

Overexpression of HIF-1alpha and 2alpha was significantly associated with increased tumor angiogenesis and VEGF expression, while HIF-2alpha was linked with upregulation of TP. None of these factors were associated with T-stage and tumor grade. Although HIFs did not relate significantly with prognosis, patients with HIF-1/2 expression who failed to switch-on VEGF or intratumoral angiogenesis had a favorable outcome.

CONCLUSION

Hypoxia inducible factors are upregulated in a large proportion of gallbladder adenocarcinomas, a feature strongly related to increased expression of VEGF and intensified angiogenesis.

A quantitative analysis of lymphatic vessels in human breast cancer, based on LYVE-1 immunoreactivity

This study was undertaken to determine the highly sensitive method for detecting tumour lymphatic vessels in all the fields of each slide (LV), lymphatic microvessel density (LMVD) and lymphatic vessel invasion (LVI) and to compare them with other prognostic parameters using immunohistochemical staining with polyclonal (PCAB) and monoclonal antibodies (MCAB) to the lymphatic vessel endothelial hyaluronan receptor-1 (LYVE-1), and the pan-endothelial marker factorVIII in a series of 67 human breast cancers. In all LYVE-1-stained sections, LV (some of which contained red blood cells) were frequently found localised in extralobular stroma, dermis, connective tissue stroma and adjacent to artery and vein, but were rare within the intralobular stroma or the tumour body (3/67 cases) or areas of widespread invasion. In contrast small blood vessels were observed in intra- and extralobular stroma in the factor VIII-stained sections. Quantitation of vessel numbers revealed that LYVE-1/PCAB detected a significantly larger number of LV than either H&E or LYVE-1/MCAB (P<0.0001). LYVE-1/PCAB detected LVI in 25/67 cases (37.3%) and their presence was significantly associated with both lymph node metastasis (χ²=4.698, P=0.0248) and unfavourable overall survival (OS) (P=0.0453), while not relapse- free survival (RFS) (P=0.2948). LMVD had no influence for RFS and OS (P=0.4879, P=0.1463, respectively). Our study demonstrates that immunohistochemistry with LYVE-1/PCAB is a highly sensitive method for detecting tumour LV/LVI in breast cancer and LVI is a useful prognostic indicator for lymphatic tumour dissemination.

Use of novel monoclonal antibodies to determine the expression and distribution of the hypoxia regulatory factors PHD-1, PHD-2, PHD-3 and FIH in normal and neoplastic human tissues

AIMS

The cellular response to hypoxia includes the hypoxia inducible factor (HIF)-induced transcription of genes involved in diverse processes such as glycolysis, angiogenesis and the growth of experimental tumours. Regulation of the level of hypoxia inducible factors 1alpha and 2alpha (HIF-1alpha and HIF-2alpha) is a primary determinant of HIF activity. Recent biochemical and candidate gene approach studies have led to the discovery of three HIF-regulatory prolyl hydroxylases, PHD-1, -2 and -3 and an asparaginyl hydroxylase, also known as FIH (factor inhibiting HIF). In this study, we raised and characterized monoclonal antibodies against PHD-1, PHD-2, PHD-3 and FIH.

METHODS AND RESULTS

Immunohistochemistry of normal tissues with these monoclonal antibodies demonstrated a wide distribution in epithelial cells, stromal cells and leucocytes, with cytoplasmic staining predominating over nuclear staining. A preliminary study of tumours showed variable staining in tumour, stromal and inflammatory cells. While all tumour types showed some positive staining with each antibody, the overall pattern suggested a slight decrease in the amount of staining seen with PHD-1, -2 and -3 and an increase in FIH staining in neoplasia compared with corresponding normal tissues.

CONCLUSIONS

These monoclonal antibodies will allow further larger scale studies to determine the significance of PHD and FIH expression in neoplasia.

The expression and cellular localization of phosphorylated VEGFR2 in lymphoma and non-neoplastic lymphadenopathy: an immunohistochemical study

AIMS

To study the expression of phosphorylated vascular endothelial growth factor receptor 2 (VEGFR2), a membrane-bound tyrosine kinase receptor to vascular endothelial growth factor, in lymphoma and non-neoplastic lymphadenopathy.

METHODS AND RESULTS

Archival cases (89 cases of lymphoma and 17 cases of non-neoplastic lymphadenopathy) were studied immunohistochemically with three monoclonal antibodies to the different autophosphorylation sites in the cytoplasmic tail of the receptor. There was increased expression of this receptor in lymphoma and particularly in all cases of peripheral T-cell lymphoma. In this category, there was nuclear re-location of this receptor.

CONCLUSIONS

This very interesting finding raises the possibility that VEGFR2 may be involved in the transcriptional regulation of this disease. Small molecule inhibitors to this receptor may therefore be a useful adjunct in the therapy of this disease.

LYVE-1 immunohistochemical assessment of lymphangiogenesis in endometrial and lung cancer

AIMS/METHODS

Normal and malignant pulmonary and endometrial tissues were analysed for lymphatic vessels to assess the process of lymphangiogenesis and its role at these sites, using specific immunostaining for LYVE-1 and the panendothelial marker CD31.

RESULTS

Lymphatics were clearly demonstrated in some normal tissues (myometrium, bronchial submucosa, and intestinal submucosa), but not in others (endometrium and alveolar tissue). LYVE-1 positive lymphatic vessels were detected at the tumour periphery of endometrial and lung carcinomas, but not within the main tumour mass. Double staining for LYVE-1 and the MIB1 proliferation marker revealed a higher proliferation index in lymphatic endothelial cells at the invading front of endometrial carcinomas, compared with myometrial areas distal to the tumour. Lung and endometrial carcinomas did not have an intratumorous lymphatic network.

CONCLUSIONS

Although lymphangiogenesis may occur at the invading tumour front, incorporated lymphatics do not survive. Therefore, the dissemination of cancer cells through the lymphatics may occur by invasion of peripheral cancer cells into the adjacent normal lymphatics, or through shunts eventually produced at the invading tumour front as a consequence of active angiogenesis and lymphangiogenesis.

The transcription factor DEC1 (stra13, SHARP2) is associated with the hypoxic response and high tumour grade in human breast cancers

DEC1, also known as SHARP-2 or Stra13, plays important roles in embryonic development, proliferation, apoptosis and cell differentiation in the mouse. DEC1 was recently identified as hypoxically induced in cDNA microarray studies of the human renal carcinoma cell line RCC4, to be regulated through hypoxia-inducible factor (HIF)-1α and via HIF-1α, able to block adipocyte differentiation. Nevertheless, its distribution and role in hypoxia and differentiation in human breast cancer are unknown. We therefore examined the pattern and level of expression of DEC1 using immunohistochemistry in whole tissue sections in normal, in situ and invasive breast carcinomas, and correlated the level of expression of DEC1 and clinicopathological factors and hypoxic tumour markers in 253 invasive carcinomas on tissue microarrays. We observed an increase in DEC1 expression during progression from normal to in situ and invasive carcinoma. Expression was not restricted to the tumour cell element but was also observed in endothelial, fibroblasts and inflammatory cells. There was a significant positive correlation between DEC1 and tumour grade (P=0.01), HIF-1α (P=0.04) and the hypoxically regulated gene angiogenin (P<0.0001), but no significant associations were observed with patient age (P=0.15), lymph node status (P=0.8), tumour size (P=0.3), oestrogen receptor (P=0.45), epidermal growth factor receptor (P=0.27) or Chalkley vessel count (P=0.45). There was no difference in relapse-free (P=0.84) or overall (P=0.78) survival. These findings suggest that DEC1 plays an important role in the progression to invasive breast cancer and that it may provide a mechanism by which hypoxia blocks tumour differentiation, and may contribute to a more aggressive phenotype. Reversing this phenotype may alter the biological behaviour of individual tumours.

Neoplastic stroma and epithelium show up-regulation of platelet-derived endothelial cell growth factor/thymidine phosphorylase in colorectal carcinomas but not adenomas

Tumor angiogenesis, a crucial step in tumor growth and progression, is regulated by an increasing number of angiogenic factors. One of those is platelet-derived endothelial cell growth factor, recently shown to bethymidine phosphorylase (TP), which reversibly catalyzes the phosphorylation of thymidine to deoxyribose-1-phosphate and thymine. TP overexpression in tumors has been reported, but the differential expression of this enzyme in the colorectal adenoma-carcinoma sequence has not been examined in detail. In this study we analyzed 16 hyperplastic polyps, 37 solitary tubular and tubulovillous adenomas (ranging from 1 to 7.5cm, median 3.2cm), and 47 cases of colorectal carcinomas arising on the basis of pre-existing adenomas (25 cases were Dukes' A, 10 Dukes' B and 12 Dukes' C). Non-neoplastic colonic mucosa was also examined separately from all the above carcinoma cases. All samples were stained for TP and assessed for vascularity. Normal mucosa, hyperplastic polyps, and all but three adenomas and the adenomatous parts of the invading tumors did not show any epithelial cell positivity, and only occasional macrophages and fibroblasts showed weak cytoplasmic immunoreactivity for TP. Neoplastic cells in the carcinomatous part of the tumors were positive for TP in 18 out of 47 (36%) cases. Both nuclear and cytoplasmic staining was detected but in a few cases only one of these was present. There was a highly significant difference between TP expression in neoplastic epithelial cells in adenomas compared with carcinomas (p=0.0001). The same was true when the immunoreactivity of the stromal cells was compared (p=0.0001). Areas with high angiogenesis such as those at the invading edge of the tumor showed intense epithelial, endothelial and stromal TP immunoreactivity. These results show up-regulation of a major angiogenic pathway in both the tumor epithelium and stromal cells with progression from adenoma to carcinoma, and suggest TP may be a candidate target for therapy.

Lactate dehydrogenase-5 (LDH-5) overexpression in non-small-cell lung cancer tissues is linked to tumour hypoxia, angiogenic factor production and poor prognosis

Lactate dehydrogenase-5 (LDH-5) catalyses the reversible transformation of pyruvate to lactate, having a principal position in the anaerobic cellular metabolism. Induction of LDH-5 occurs during hypoxia and LDH-5 transcription is directly regulated by the hypoxia-inducible factor 1 (HIF1). Serum LDH levels have been correlated with poor prognosis and resistance to chemotherapy and radiotherapy in various neoplastic diseases. The expression, however, of LDH in tumours has never been investigated in the past. In the present study, we established an immunohistochemical method to evaluate the LDH-5 overexpression in tumours, using two novel antibodies raised against the rat muscle LDH-5 and the human LDH-5 (Abcam, UK). The subcellular patterns of expression in cancer cells were mixed nuclear and cytoplasmic. In direct contrast to cancer cells, stromal fibroblasts were reactive for LDH-5 only in a minority of cases. Serum LDH, although positively correlated with, does not reliably reflect the intratumoral LDH-5 status. Lactate dehydrogenase-5 overexpression was directly related to HIF1alpha and 2alpha, but not with the carbonic anhydrase 9 expression. Patients with tumours bearing high LDH-5 expression had a poor prognosis. Tumours with simultaneous LDH-5 and HIF1alpha (or HIF2alpha) overexpression, indicative of a functional HIF pathway, had a particularly aggressive behaviour. It is concluded that overexpression of LDH-5 is a common event in non-small-cell lung cancer, can be easily assessed in paraffin-embedded material and provides important prognostic information, particularly when combined with other endogenous markers of hypoxia and acidity.

The angiogenic receptor KDR is widely distributed in human tissues and tumours and relocates intracellularly on phosphorylation. An immunohistochemical study

AIMS

Angiogenesis is an important factor in tumour growth and metastasis. Vascular endothelial growth factor receptor 2 (VEGFR-2) or KDR plays a crucial role in angiogenesis. The aim of this study was to raise and characterize antibodies against phosphorylated KDR which could be used for studies on human tissues to assess KDR activation and novel inhibitors of KDR activation in clinical trials.

METHODS AND RESULTS

Three monoclonal antibodies and one rabbit polyclonal antiserum were produced. The specificity of the antibodies was confirmed by ELISA. One of the mouse antibodies and the rabbit polyclonal antiserum reacted with a 200-kDa band on a Western blot of human umbilical vein endothelial cell (HUVEC) lysates, the molecular weight of KDR. Immunohistochemical staining showed that phosphorylated KDR is present in a wide variety of normal tissues including liver, colon and placenta, and is not restricted to endothelium. It was also present in a number of human tumours including breast carcinomas, colonic carcinomas and non-Hodgkin's lymphomas. The pattern of staining was membranous, cytoplasmic and nuclear.

CONCLUSIONS

This study has shown that phosphorylated KDR is present in a wide variety of tumour and tissue types and is not confined to endothelium.

Lymphoproliferative disorders in Oxford renal transplant recipients

BACKGROUND

Increased cancer incidence, particularly lymphoproliferative disease, is a complication of immunosuppression in organ transplantation. Non-Hodgkin's lymphomas (NHLs) occur frequently during the first year after transplantation, more so in North America than in Europe.

METHODS

This study audited and correlated the demographic, clinical, pathological, and outcome features of post-transplant lymphoproliferative disorders (PTLDs) in a large centre in Oxford, and assessed whether the time of onset fitted more with the European or North American pattern.

RESULTS

There were 1383 renal transplants in the study period and 27 patients developed lymphoma: 26 NHLs and one Hodgkin's disease (1.95%). Four of the patients never received cyclosporin. The mean time of diagnosis after transplant was 46 months. Most tumours (21/27) presented extranodally. Management included reduction of immunosuppression, surgical excision, antiviral treatment, radiotherapy, and chemotherapy. Three patients presented in the first post-transplant year-0.34% of cyclosporin managed patients-similar to the North American incidence, although the incidence of extranodal late PTLDs was also high (mean onset, 36 months v 15 months international mean). Post-transplant lymphomas were the most common malignancy associated with death in transplant patients.

CONCLUSIONS

PTLDs occurred in 2% of renal transplant patients, presenting both in the first year in association with cyclosporin use, as in North America, but also in subsequent years, giving an overall presentation time later than the international mean. The disease usually presented extranodally, accounting for the wide range of symptoms and signs. Despite awareness and active management, the disease contributed to death in more that 50% of patients with PTLDs.

Carbonic anhydrase XII is a marker of good prognosis in invasive breast carcinoma

Hypoxia and pH influence gene expression in tumours, and it is becoming increasingly clear that the pattern of genes expressed by a tumour determines its growth and survival characteristics. Hypoxia-inducible factor-1 (HIF-1) is a key mediator of the cellular response to hypoxia and high HIF-1 expression has been identified as a poor prognostic factor in tumours. Recently, we identified the tumour-associated carbonic anhydrases (CA), CA9 and CA12 as hypoxia-inducible in tumour cell lines. Furthermore, we identified CA IX to be a poor prognostic factor in breast cancer. The aim of this study was to assess the prognostic significance of CA XII. CA XII expression was studied by immunohistochemistry in a series of 103 cases of invasive breast cancer and any association with recognised prognostic factors or relation with the outcome was examined. CA XII expression was present in 77 out of 103 (75%) cases and was associated with lower grade (P=0.001), positive estrogen receptor status (P<0.001), and negative epidermal growth factor receptor status (P<0.001). Furthermore, although CA XII expression was associated with an absence of necrosis (P<0.001), expression of CA XII in some high-grade tumours was induced in regions directly adjacent to morphological necrosis. Additionally, using univariate analysis, CA XII positive tumours were associated with a lower relapse rate (P=0.04) and a better overall survival (P=0.01). In conclusion, CA XII expression is influenced both by factors related to differentiation and hypoxia in breast cancer in vivo and CA XII expression is associated with a better prognosis in an unselected series of invasive breast carcinoma patients.

Hypoxia inducible factor 1alpha and 2alpha overexpression in inflammatory bowel disease

AIMS

Hypoxia inducible factors 1alpha and 2alpha (HIF1alpha and HIF2alpha) are hypoxia regulated transcriptional factors, which control the expression of a variety of genes responsible for angiogenesis, glycolysis, and the inhibition of apoptosis. Because angiogenesis and tissue regeneration are integral components of the inflammatory process, this study was designed to investigate the role of HIFalpha molecules in inflammatory bowel disease.

METHODS

Surgical specimens from patients with active ulcerative colitis (UC) and Crohn's disease (CD) were assessed immunohistochemically for HIF1alpha and HIF2alpha reactivity, and the expression of these molecules was compared with the expression of the angiogenic factors thymidine phosphorylase (TP), vascular endothelial growth factor (VEGF), and VEGF-KDR activated vasculature. The vascular density of the lesions was also assessed using anti-CD31 immunostaining.

RESULTS

HIF1alpha was expressed focally (epithelial cells, stromal fibroblasts, and myocytes) in both UC and CD, whereas HIF2alpha was expressed focally in UC and diffusely in CD. TP expression was uniformly positive in both diseases. VEGF expression was absent in CD, and weakly positive in UC. The VEGF-KDR reactivity of the submucosal vasculature was only slightly increased in UC and CD compared with normal tissue. The inflammatory cells stained with HIF2alpha and TP in all cases, but the reactivity was generalised in CD and focal in UC. In both diseases, vascular density was significantly higher than that seen in normal tissue.

CONCLUSIONS

The discordant expression of HIF2alpha and VEGF in CD suggests an inherent deficiency of the intestine to respond to various stresses by the induction of VEGF. This finding should be investigated further.

Tumours of histiocytes and accessory dendritic cells: an immunohistochemical approach to classification from the International Lymphoma Study Group based on 61 cases

Neoplasms of histiocytes and dendritic cells are rare, and their phenotypic and biological definition is incomplete. Seeking to identify antigens detectable in paraffin-embedded sections that might allow a more complete, rational immunophenotypic classification of histiocytic/dendritic cell neoplasms, the International Lymphoma Study Group (ILSG) stained 61 tumours of suspected histiocytic/dendritic cell type with a panel of 15 antibodies including those reactive with histiocytes (CD68, lysozyme (LYS)), Langerhans cells (CD1a), follicular dendritic cells (FDC: CD21, CD35) and S100 protein. This analysis revealed that 57 cases (93%) fit into four major immunophenotypic groups (one histiocytic and three dendritic cell types) utilizing six markers: CD68, LYS, CD1a, S100, CD21, and CD35. The four (7%) unclassified cases were further classifiable into the above four groups using additional morphological and ultrastructural features. The four groups then included: (i) histiocytic sarcoma (n=18) with the following phenotype: CD68 (100%), LYS (94%), CD1a (0%), S100 (33%), CD21/35 (0%). The median age was 46 years. Presentation was predominantly extranodal (72%) with high mortality (58% dead of disease (DOD)). Three had systemic involvement consistent with 'malignant histiocytosis'; (ii) Langerhans cell tumour (LCT) (n=26) which expressed: CD68 (96%), LYS (42%), CD1a (100%), S100 (100%), CD21/35 (0%). There were two morphological variants: cytologically typical (n=17) designated LCT; and cytologically malignant (n=9) designated Langerhans cell sarcoma (LCS). The LCS were often not easily recognized morphologically as LC-derived, but were diagnosed based on CD1a staining. LCT and LCS differed in median age (33 versus 41 years), male:female ratio (3.7:1 versus 1:2), and death rate (31% versus 50% DOD). Four LCT patients had systemic involvement typical of Letterer-Siwe disease; (iii) follicular dendritic cell tumour/sarcoma (FDCT) (n=13) which expressed: CD68 (54%), LYS (8%), CD1a (0%), S100 (16%), FDC markers CD21/35 (100%), EMA (40%). These patients were adults (median age 65 years) with predominantly localized nodal disease (75%) and low mortality (9% DOD); (iv) interdigitating dendritic cell tumour/sarcoma (IDCT) (n=4) which expressed: CD68 (50%), LYS (25%), CD1a (0%), S100 (100%), CD21/35 (0%). The patients were adults (median 71 years) with localized nodal disease (75%) without mortality (0% DOD). In conclusion, definitive immunophenotypic classification of histiocytic and accessory cell neoplasms into four categories was possible in 93% of the cases using six antigens detected in paraffin-embedded sections. Exceptional cases (7%) were resolvable when added morphological and ultrastructural features were considered. We propose a classification combining immunophenotype and morphology with five categories, including Langerhans cell sarcoma. This simplified scheme is practical for everyday diagnostic use and should provide a framework for additional investigation of these unusual neoplasms.

Thymidine phosphorylase expression in normal, hyperplastic and neoplastic prostates: correlation with tumour associated macrophages, infiltrating lymphocytes, and angiogenesis

Thymidine phosphorylase is an angiogenic factor primarily expressed by cancer cells, stromal cells and tumour-associated macrophages in many human malignancies. These different types of thymidine phosphorylase-expressing cells, however, may have a distinct place in the angiogenic process, and this question was addressed in the present study. A series of 20 normal/hyperplastic prostate glands and 60 prostate carcinomas was investigated by immunohistochemistry, using specific antibodies for thymidine phosphorylase (P-GF.44C), tumour-associated macrophages (CD68), endothelium (CD31) and prostate specific antigen (ER-PR8). Thymidine phosphorylase expression by normal and hyperplastic epithelial or stromal cells occurred almost exclusively in the context of an intense lymphocytic infiltrate. High thymidine phosphorylase cancer cells and thymidine phosphorylase stromal cells expression was associated with high angiogenesis in prostate carcinomas, and this significant association was extended to include both tumour-associated macrophages and tumour-infiltrating lymphocytes. Thymidine phosphorylase expression and tumour-infiltrating lymphocytes were related inversely with prostate specific antigen reactivity. In conclusion, thymidine phosphorylase is a major angiogenic factor in prostate carcinomas and its up-regulation is likely to occur in the context of a host immune response.

Ki67 protein: the immaculate deception?

This article updates our previous review of Ki67 published in Histopathology 10 years ago. In this period the numbers of papers published featuring this antibody has increased 10-fold from 338 to 3489 indicating the considerable enthusiasm with which this antibody has been studied. This review attempts to provide an update on the characterization of the Ki67 protein, its function and its use as a prognostic or diagnostic tool.

Vascular phenotype in angiogenic and non-angiogenic lung non-small cell carcinomas

We have previously described a group of non-small cell lung carcinomas without morphological evidence of neo-angiogenesis. In these tumours neoplastic cells fill up the alveoli and the only vessels present appear to belong to the trapped alveolar septa. In the present study we have characterised the phenotype of the vessels present in these non-angiogenic tumours, in normal lung and in angiogenic non-small cell lung carcinomas. The vessels, identified by the expression of CD31, were scored as mature when expressing the epitope LH39 in the basal membrane and as newly formed when expressing alphaVbeta3 on the endothelial cells and/or lacking LH39 expression. In the nine putative non-angiogenic cases examined, the vascular phenotype of all the vessels was the same as that of alveolar vessels in normal lung: LH39 positive and alphaVbeta3 variable or negative. Instead in 104 angiogenic tumours examined, only a minority of vessels (mean 13.1%; range 0--60%) expressed LH39, while alphaVbeta3 (in 45 cases) was strongly expressed on many vessels (mean 55.5%; range 5--90%). We conclude that in putative non-angiogenic tumours the vascular phenotype is that of normal vessels and there is no neo-angiogenesis. This type of cancer may be resistant to some anti-angiogenic therapy and different strategies need to be developed.

Ki67 protein: the immaculate deception?

This article updates our previous review of Ki67 published in Histopathology 10 years ago. In this period the numbers of papers published featuring this antibody has increased 10-fold from 338 to 3489 indicating the considerable enthusiasm with which this antibody has been studied. This review attempts to provide an update on the characterization of the Ki67 protein, its function and its use as a prognostic or diagnostic tool.

The angiogenic "vascular endothelial growth factor/flk-1(KDR) receptor" pathway in patients with endometrial carcinoma: prognostic and therapeutic implications

BACKGROUND

Vascular endothelial growth factor (VEGF) is an important endothelial cell mitogen associated with increased angiogenesis and aggressive tumor behavior. Its stimulating effect on endothelial cells basically is dependent on the presence of specific VEGF receptors, such as the flk-1(KDR) receptor. This study investigates the roles of VEGF and of a functionally intact angiogenic pathway, "VEGF/flk-1(KDR)," in patients with endometrial carcinoma and their significance in prognosis and therapy.

METHODS

A series of 121 endometrial carcinomas were studied. The expression of VEGF by endometrial tumor cells was assessed using the monoclonal antibody (MoAb) VG1. VEGF/KDR complexes on tumor endothelium or activated microvessel density (aMVD) were identified using the MoAb 11B5. In addition, the standard microvessel density (sMVD) was assessed with anti-CD31. In all tumors, the alkaline phosphatase/antialkaline phosphatase technique was employed. A Fisher exact test or an unpaired, two-tailed t test was used for testing correlations between categoric tumor variables, whereas a log-rank test was used to determine statistical differences between life tables. A Cox proportional hazards model was used to assess the effect of tumor variables on overall survival.

RESULTS

Cytoplasmic VEGF expression in > 50% of tumor cells was associated significantly with aMVD (P < 0.0001) and with sMVD (P < 0.003). In univariate survival analysis, VEGF (P = 0.0002), aMVD (P = 0.001), and sMVD (P = 0.0009) were significant prognostic variables. Equally important were the histologic parameters tumor type (P = 0.03), tumor grade (P = 0.003), and disease stage (P < 0.0001). In multivariate analysis, disease stage was the most important independent prognostic factor (P < 0.0001), followed by VEGF/KDR (P < 0.01), and VEGF (P < 0.04). Furthermore, VEGF and VEGF/KDR were the only independent prognostic variables for patients with Stage I endometrioid adenocarcinoma.

CONCLUSIONS

sMVD and the angiogenic factor VEGF are important indicators of a poor prognosis in patients with endometrial carcinoma. VEGF/KDR complexes define a subgroup of patients with endometrial carcinoma with an even worse prognosis.

Squamous cell head and neck cancer: evidence of angiogenic regeneration during radiotherapy

BACKGROUND AND PURPOSE

Intra-tumoural neoangiogenesis is an essential process for tumour progression. Although intensification of angiogenic pathways during cytotoxic therapy has been reported by a few experimental studies, the role of angiogenesis in response to radiotherapy is unclear. We recently reported an adverse effect of intense angiogenesis in the radiotherapy outcome of squamous cell head and neck cancer (SCHNC). In the present study we investigated the radiotherapy-induced changes in the microvessel density (MVD) and in the expression of the angiogenic factor thymidine phosphorylase (TP) in SCHNC.

PATIENTS AND METHODS

Twenty-four patients with SCHNC underwent a biopsy of the primary lesion immediately before and after delivery of 20Gy of conventionally fractionated radiotherapy. The MVD and the expression of TP was assessed with immunohistochemistry.

RESULTS

The irradiated samples were composed of cancer cell islets or bands, immersed within avascular degenerated tissue. In tumours that did not reach complete response after the end of radiotherapy, these viable cancer tissue areas had a significantly higher MVD (p=0.006) and increased percentage of cancer cells with nuclear TP expression (p=0.0004) than the MVD and the TP expression noted in specimens before radiotherapy. TP expression in these islets was directly related to the MVD (p=0.004, r=0.56).

CONCLUSION

The present study supports the idea that intensified angiogenic growth (angiogenic regeneration) during radiotherapy is associated with failure of radiotherapy.

Expression of hypoxia-inducible carbonic anhydrase-9 relates to angiogenic pathways and independently to poor outcome in non-small cell lung cancer

Carbonic anhydrase-9 (CA9), a transmembrane enzyme with an extracellular active site, is involved in the reversible metabolism of the carbon dioxide to carbonic acid. Up-regulation of CA by hypoxia and the hypoxia-inducible factor (HIF) pathway has been recently postulated (Wykoff et al. Cancer Res., 60: 7075-7083, 2000). In the present study we examined the expression of this enzyme in non-small cell lung cancer. Of 107 cases analyzed, 39 (36.4%) had strong membrane/cytoplasmic expression of CA9 and were grouped as positive. The staining was confined around areas of necrosis, and a significant association of CA9 expression with the extent of necrosis was noted (P = 0.004). Nevertheless, 38 of 74 cases with focal or extensive necrosis did not express CA9. CA9 expression was more frequent in the squamous cell histology (P = 0.001) and with advanced T stage (P = 0.009). A significant coexpression of CA9 with platelet-derived endothelial cell growth factor and basic fibroblast growth factor receptor expression was noted. Double staining of CA9 with anti-CD31 monoclonal antibody revealed an overall higher microvessel density in the areas expressing CA9 than in negative areas (P = 0.0005). Thirty-one of 38 CA9-positive cases were positive for HIF1a/HIF2a, but HIF positivity was a more common event (68 of 107) and their patterns of expression were diffuse (not confined in the necrotic areas). A direct association of CA9 expression with epidermal growth factor receptor, c-erbB-2, and MUC1 expression was also noted (P < 0.04). Survival analysis showed that CA9 expression is related to poor prognosis. CA9 expression in tumors with low vascularization defined a prognosis similar to the one of patients with highly angiogenic tumors. Multivariate analysis revealed that CA9 expression is a significant prognostic factor independent of angiogenesis. We conclude that CA9 is an important molecule in non-small cell lung cancer, the up-regulation of which occurs in highly hypoxic/necrotic regions of the tumors. The expression of CA9 is linked to the expression of a constellation of proteins involved in angiogenesis, apoptosis inhibition, and cell-cell adhesion disruption, which explains the strong association of CA9 with poor outcome.

Hypoxia-regulated carbonic anhydrase-9 (CA9) relates to poor vascularization and resistance of squamous cell head and neck cancer to chemoradiotherapy

PURPOSE

Carbonic anhydrases are proteins involved in the catalytic hydration of carbon dioxide to carbonic acid. Recent studies show that carbonic anhydrase 9 (CA9) is up-regulated by hypoxia and that its immunohistochemical tissue distribution follows the distribution of the radiosensitizer pimonidazole (C. C. Wykoff et al., Cancer Res. 60: 7075-7083, 2001). Therefore, CA9 expression may show hypoxia levels of clinical importance.

EXPERIMENTAL DESIGN

We assessed the expression of CA9 and the microvessel density (MVD; CD31-positive) in 75 locally advanced squamous cell head and neck cancers treated with concurrent chemoradiotherapy with carboplatin.

RESULTS

Strong membrane/cytoplasmic CA9 expression, noted in 20/75 (26.6%) tumors, mainly occurred in tumors with very poor vascularization (expression in 63% versus 14%; P < 0.0001), was located around areas of focal necrosis, and was related to poor complete response rate (40% versus 70%; P = 0.02). These observations suggested that CA9 might be a marker of clinically important hypoxia. Combining the CA9 staining and the tumor angiogenicity (MVD), we identified three groups of patients: (a) hypoxic tumors; (b) euoxic highly angiogenic tumors; and (c) euoxic non-highly angiogenic tumors. Groups (a) and (b) had a very poor local relapse-free survival (P < 0.0001).

CONCLUSIONS

Stratification of patients undergoing radical radiotherapy using the CA9/MVD model may be useful for the individualization of therapeutic strategies combining antiangiogenesis and hypoxia targeting with radiotherapy.

Assessment of vascular maturation in lung and breast carcinomas using a novel basement membrane component, LH39

LH39, is a monoclonal antibody recognizing an epitope located at the lamina lucida of mature small veins and capillaries but not in newly- formed vessels of several pathological conditions including cancer. We examined the ratio of mature/immature vessels in 50 breast and 81 lung carcinomas and correlated the vascular maturation index (VMI) to different clinicopathological variables including angiogenesis. Mature vessels were defined by staining with antibodies to both LH39 and CD31, using double immunohistochemistry, whereas immature vessels stained only for CD31. VMI was defined as the percentage fraction of mature vessels (LH39 positive)/total number of vessels (CD31 positive). VMI in breast carcinomas ranged from 0-47% (median 8.75%), which was significantly lower than that observed in the normal breast cases (range 54%-70%; median 68%). The median VMI in the non-small cell lung carcinomas was 46% (range 15%-90%). There was a significant inverse correlation between high tumor VMI and absence of nodal involvement in both breast and lung tumors examined (p=0.01). Thymidine phosphorylase (TP) expression, but not vascular endothelial growth factor (VEGF) expression, was related to a low VMI showing an intense vascular remodeling in TP expressing cases. Thus, assessment of vessel maturation might be complementary to microvessel number to aid the identification of patients who might benefit from specific antiangiogenic therapies or vascular targeting treatment.

Thioredoxin expression is associated with lymph node status and prognosis in early operable non-small cell lung cancer

PURPOSE

Thioredoxin (TRX), a low molecular weight protein, exerts reduction-oxidation control over a number of transcription factors involved in cell activation and proliferation. High TRX mRNA levels have been found in lung carcinomas, a trait associated with a growth and survival advantage.

EXPERIMENTAL DESIGN

In this study, we examined the immunohistochemical expression of human TRX in normal lung and in 102 primary non-small cell lung carcinomas.

RESULTS

In normal lung, the staining for TRX was cytoplasmic in the respiratory bronchial epithelium, alveolar epithelium, and alveolar macrophages. Bronchial glandular cells demonstrated a mixed nuclear and cytoplasmic staining. In lung carcinomas, the pattern of expression for TRX was predominantly cytoplasmic and only occasionally nuclear. A strong association between absence of TRX expression and regional lymph node negativity was observed (P = 0.004). High proliferation index, as detected with Ki-67 antibody, was associated with high TRX expression (P = 0.02). A significant correlation between high cytoplasmic p53 reactivity and low TRX expression was observed (P = 0.04). No association with grade, tumor stage, histology, or bcl-2 was noted. A significant coexpression of TRX with human activator protein endonuclease 1 was recorded (P = 0.04). Absence of TRX expression was associated with a better outcome (P < 0.05).

CONCLUSIONS

We conclude that overexpression of TRX in non-small cell lung carcinomas is indicative of a more aggressive tumor phenotype and is associated with bad prognostic features and possibly with a poorer outcome.

Angiogenesis and p53 expression in the colorectal adenoma-carcinoma sequence

Angiogenesis, the formation of new vessels, is essential for tumor growth and metastasis. Mutations of p53 tumor suppressor gene are frequent and play an important role in colorectal oncogenesis. A role of p53 as an angiogenesis inhibitor has also been proposed. We evaluated angiogenesis and p53 expression in 16 hyperplastic polyps, 35 solitary tubular and tubulovillous adenomas, and 47 cases of sporadic colorectal carcinomas arising on the basis of preexisting adenomas, with standard immunohistochemical techniques. The mean microvessel density (MVD) in carcinomas was significantly higher compared with the respective adenomatous part of the same tumor (27.9 vs. 7; P=0.0001). Linear regression analysis of MVD between cancerous and adenomatous areas showed a significant correlation (P = 0.0001, r = 0.56), raising the possibility that carcinomas arising from better vascularized adenomas might show increased vascularity. The MVD was significantly higher in stage C compared with stage A cases (P=0.04). p53 positivity was detected in 26 of 47 cancerous (55%) and in 14 of 47 adenomatous areas (30%; P = 0.0002). All carcinomas arising from p53-positive adenomas were also p53 positive. p53 positivity associated with a higher MVD in adenomas (P = 0.02), but not in carcinomas (P = 0.78). We conclude that angiogenesis and p53 play a critical role in colorectal neoplasia, and the process of malignant transformation in tumors arising from highly angiogenic adenomas, particularly those carrying p53 mutations, is accelerated with rapid tumor progression from stage to stage, indicating a more aggressive tumor phenotype.

Relation of hypoxia inducible factor 1 alpha and 2 alpha in operable non-small cell lung cancer to angiogenic/molecular profile of tumours and survival

Hypoxia inducible factors HIF1alpha and HIF2alpha are important proteins involved in the regulation of the transcription of a variety of genes related to erythropoiesis, glycolysis and angiogenesis. Hypoxic stimulation results in rapid increase of the HIF1alpha and 2alpha protein levels, as a consequence of a redox-sensitive stabilization. The HIFalphas enter the nucleus, heterodimerize with the HIF1beta protein, and bind to DNA at the hypoxia response elements (HREs) of target genes. In this study we evaluated the immunohistochemical expression of these proteins in 108 tissue samples from non-small-cell lung cancer (NSCLC) and in normal lung tissues. Both proteins showed a mixed cytoplasmic/nuclear pattern of expression in cancer cells, tumoural vessels and tumour-infiltrating macrophages, as well as in areas of metaplasia, while normal lung components showed negative or very weak cytoplasmic staining. Positive HIF1alpha and HIF2alpha expression was noted in 68/108 (62%) and in 54/108 (50%) of cases respectively. Correlation analysis of HIF2alpha expression with HIF1alpha expression showed a significant association (P< 0.0001, r = 0.44). A strong association of the expression of both proteins with the angiogenic factors VEGF (P< 0.004), PD-ECGF (P< 0.003) and bFGF (P< 0.04) was noted. HIF1alpha correlated with the expression of bek-bFGF receptor expression (P = 0.01), while HIF2alpha was associated with intense VEGF/KDR-activated vascularization (P = 0.002). HIF2alpha protein was less frequently expressed in cases with a medium microvessel density (MVD); a high rate of expression was noted in cases with both low and high MVD (P = 0.006). Analysis of overall survival showed that HIF2alpha expression was related to poor outcome (P = 0.008), even in the group of patients with low MVD (P = 0.009). HIF1alpha expression was marginally associated with poor prognosis (P = 0.08). In multivariate analysis HIF2alpha expression was an independent prognostic indicator (P = 0.006, t-ratio 2.7). We conclude that HIF1alpha and HIF2alpha overexpression is a common event in NSCLC, which is related to the up-regulation of various angiogenic factors and with poor prognosis. Targeting the HIF pathway may prove of importance in the treatment of NSCLC.

Plasminogen activator inhibitor-1 as a measure of vascular remodelling in breast cancer

The generation of urokinase plasminogen activator (uPA) by tumours is an important pathway for neoplastic cell invasion and metastasis. Indeed in several tumour types, elevated levels of uPA, its receptor (uPAR) or its inhibitor plasminogen activator inhibitor-1 (PAI-1) is associated with a poorer prognosis. Since endothelial cells also use this proteolytic system to remodel the extracellular matrix during angiogenesis and since angiogenesis, as assessed by microvessel density, is also a predictor of patient survival, this study was designed to investigate the relationship between angiogenesis and the urokinase system in breast tumours. The aims were to assess whether the uPA, uPAR and/or PAI-1 correlates with angiogenic activity and could therefore be a useful objective clinical measure of tumour neovascularization; and to clarify whether the poor outcome associated with high levels of the urokinase system is due to its association with angiogenesis. The study also sought to examine the relationship between the uPA system and vessel remodelling using loss of a basement membrane epitope (LH39) normally associated with established capillaries. The cytosolic levels of uPA, PAI-1 and uPAR were therefore measured by enzyme linked immunoabsorbent assay, together with tumour vascularity, in 136 well-characterized invasive breast carcinomas. There were significant relationships between uPA and uPAR (Spearman r=0.37, p<0.0001), uPA and PAI-1 (Spearman r=0.19, p=0.03) and between uPAR and PAI-1 (Spearman r=0.23 p=0.01). A significant correlation was also observed between PAI-1 and vessel remodelling (Spearman r=0.34, p=0.04), patient age (p=0.01), nodal status (p=0.047) and tumour grade (p=0.04), but no association between tumour vascularity and PAI (p=0.96), uPA (p=0.69) or uPAR (p=0.81) was present. No significant association was seen between any of the urokinase variables and expression of the angiogenic factor thymidine phosphorylase. Furthermore, no significant associations were found between any of the studied parameters and overall survival in a univariate analysis of the cancer patients. A multivariate Cox proportional hazard model of overall survival showed that uPA (p=0.15), but not uPAR (p=0.52) or PAI-1 (p=0.61), gave no additional prognostic information. These findings show that uPA may work via an independent pathway to angiogenesis and therefore combined blockade of uPA and angiogenesis may have additional therapeutic benefits. It also shows, as recently demonstrated in animal models, that PAI-1 may be a key regulator of vascular remodelling in human cancer.

Prognostic significance of a novel hypoxia-regulated marker, carbonic anhydrase IX, in invasive breast carcinoma

PURPOSE

To assess the frequency of expression and the prognostic significance of a hypoxia-regulated marker, carbonic anhydrase IX (CA IX), in a cohort of patients with invasive breast cancer.

PATIENTS AND METHODS

CA IX expression was evaluated by immunohistochemistry with a murine monoclonal antibody, M75, in a series of 103 women treated surgically for invasive breast cancer. The majority of patients were treated with adjuvant hormonal or chemotherapy. The frequency of CA IX expression, its association with recognized prognostic factors, and the relationship with outcome was evaluated by univariate and multivariate statistical analyses.

RESULTS

CA IX expression was present in 49 (48%) of 103 cases. The level of CA IX expression was found to be significantly associated with tumor necrosis (P <.001), higher grade (P =.02), and negative estrogen receptor status (P <.001). Furthermore, CA IX expression was associated with a higher relapse rate (P =.004) and a worse overall survival (P =.001). By multivariate analysis, CA IX was also shown to be an independent predictive factor for overall survival (hazard ratio, 2.61; 95% confidence interval, 1.01 to 6.75, P =.05).

CONCLUSION

CA IX expression was associated with worse relapse-free survival and overall survival in an unselected cohort of patients with invasive breast carcinoma. The potential role of CA IX as a marker of hypoxia within breast carcinomas was also indicated by a significant association with necrosis. Further work assessing its prognostic significance in breast cancer is warranted, particularly interactions with radiotherapy and chemotherapy resistance.

Tumor specific activation of the VEGF/KDR angiogenic pathway in a subset of locally advanced squamous cell head and neck carcinomas

Vascular endothelial growth factor (VEGF) and its receptors, Flt-1 and flk-1(KDR), constitute an important angiogenic pathway which, under hypoxic conditions, is up-regulated in many solid tumours. We used the monoclonal antibody 11B5, specific for recognizing VEGF expression and the 'VEGF/flk-1(KDR) complex' on tumour endothelium, to assess free VEGF protein expression and VEGF/receptor activated microvessel density (aMVD) in a series of 104 inoperable locally advanced squamous cell carcinomas of the head and neck, treated with chemo-radiotherapy. High VEGF expression in cancer cells was strongly associated with high VEGF/receptor expression in the vasculature. The high VEGF expression and the aMVD were not associated with the standard microvessel density (sMVD), as assessed with the monoclonal antibody anti-CD31 and, were not detected in normal tissue. An increased sMVD, however, was significantly related with the expression thymidine phosphorylase (TP), and also with the nuclear accumulation of the oncoprotein p53, but neither p53 nor TP was associated with VEGF expression by cancer cells or VEGF/receptor complex aMVD. In 35% of cancer cases examined, more than 20% of the microvessels assessed with anti-CD31 also expressed the VEGF/KDR complex. The vasculature of the normal head and neck mucosa did not express the VEGF/KDR complex. There was no association between VEGF expression or VEGF/receptor complex aMVD and response to chemo-radiotherapy or patient's survival. It is concluded that activation of the angiogenic pathway VEGF/flk-1(KDR) is tumor specific in a subgroup of locally advanced squamous cell carcinomas of the head and neck. Selective destruction of this type of vasculature, using immunoconjugates directed against the VEGF/receptor complex, may prove therapeutically useful for patients with a high tumoral VEGF/flk-1(KDR) activated microvessel fraction.

The distribution and expression of the Bloom's syndrome gene product in normal and neoplastic human cells

Bloom's syndrome (BS) is an autosomal recessive disorder associated with a predisposition to cancers of all types. Cells from BS sufferers display extreme genomic instability. The BS gene product, BLM, is a 159 kDa DNA helicase enzyme belonging to the RecQ family. Here, we have analysed the distribution of BLM in normal and tumour tissues from humans using a recently characterized, specific monoclonal antibody. BLM was found to be localized to nuclei in normal lymphoid tissues, but was largely absent from other normal tissues analysed with the exception of the proliferating compartment of certain tissues. In contrast, expression of BLM was observed in a variety of tumours of both lymphoid and epithelial origin. A strong correlation was observed between expression of BLM and the proliferative status of cells, as determined by staining for markers of cell proliferation (PCNA and Ki67). We conclude that BLM is a proliferation marker in normal and neoplastic cells in vivo, and, as a consequence, is expressed at a higher level in tumours than in normal quiescent tissues.

Nuclear expression of human apurinic/apyrimidinic endonuclease (HAP1/Ref-1) in head-and-neck cancer is associated with resistance to chemoradiotherapy and poor outcome

PURPOSE

HAP1/Ref-1 endonuclease is involved in the repair of DNA strand breaks and in the activation of DNA binding of several transcription factors. HAP1 is also a potent activator of wild type p53. It therefore has multiple possible roles in the response of human cancer to radiotherapy and chemotherapy.

METHODS AND MATERIALS

The nuclear expression of HAP1 and p53 proteins was studied by immunohistochemistry in paraffin-embedded material from 95 patients with locally advanced squamous cell head-and-neck cancer (HNC) treated with radical radiotherapy (38 cases with induction platinum-based chemotherapy and 57 with concurrent platinum chemoradiotherapy).

RESULTS

HAP1 was present in the nuclei of normal epithelium and stromal cells. Loss of HAP1 nuclear expression was frequently noted in cancer cells. Tumors with high HAP1 nuclear expression (% of positive cells > mean; mean = 11%) were of good differentiation (p = 0.06) and presented frequently with advanced nodal disease (p = 0.01). High nuclear HAP1 expression was significantly associated with poor complete response rate (p = 0.00001), shorter local relapse-free interval (p < 0.0001), and poorer survival (p < 0.0008). HAP1 nuclear reactivity was inversely associated with p53 nuclear accumulation (p = 0.003). The inverse correlation between HAP1 expression and prognosis was independent of p53 status.

CONCLUSION

HAP1 nuclear expression in HNC is inversely associated with p53 nuclear accumulation and directly related to resistance to chemoradiotherapy and poor survival. Further clinical investigation is required to confirm these findings.

The angiogenic pathway "vascular endothelial growth factor/flk-1(KDR)-receptor" in rheumatoid arthritis and osteoarthritis

Active angiogenesis, together with an up-regulation of angiogenic factors, is evident in the synovium of both rheumatoid arthritis (RA) and osteoarthritis (OA). The present study assessed, by immunohistochemistry, the microvessel density in the synovium of these arthritides and in normal controls, in relation to the expression of the angiogenic factors vascular endothelial growth factor (VEGF) and platelet-derived endothelial cell growth factor (PD-ECGF) and the apoptosis-related proteins bcl-2 and p53. More importantly, using the novel 11B5 MAb, the activated "VEGF/flk-1(KDR)-receptor" microvessel density was assessed. VEGF expression in fibroblasts was diffuse in both RA and OA. Diffuse PD-ECGF expression of fibroblasts was noted in all cases of RA, while fibroblast reactivity was focal in the OA material. The standard microvessel density (sMVD), as assessed with the anti-CD31 monoclonal antibody (MAb), was higher in RA (64+/-12) and in OA (65+/-16) than in normal tissues (52+/-8; p=0.008 and 0.0004, respectively). The activated microvessel density (aMVD), assessed with the 11B5 MAb, was significantly higher in RA (29+/-10) than in OA (17+/-4; p<0.0001) and than in normal tissues (14+/-2; p<0.0001). The "activation ratio" (aMVD/sMVD) was statistically higher in RA (0.46+/-0.17) than in OA and normal synovial tissues, the latter two having a similar ratio (0.28+/-0.08 and 0.26+/-0.03, respectively). Cytoplasmic bcl-2 expression was frequent in the synovial cells of OA, but rare in RA. Nuclear p53 protein accumulation was never observed. It is suggested that the angiogenic pathway VEGF/flk-1(KDR) may play an important role in the pathogenesis of RA and OA. Thus, failure of VEGF/flk-1(KDR) activation, in the presence of increased VEGF expression, may indicate a synovium with an impaired capacity to establish a viable vasculature, consistent with the degenerative nature of OA. On the other hand, the activated angiogenesis in RA shows a functional, still pathologically up-regulated VEGF/flk-1(KDR) pathway. Whether restoration of an impaired VEGF/flk-1(KDR) pathway in OA, or inhibition of this in RA, would prove of therapeutic importance requires further investigation.

Angiogenic interactions of vascular endothelial growth factor, of thymidine phosphorylase, and of p53 protein expression in locally advanced gastric cancer

The assessment of the angiogenic profile of tumors may become an important tool as a guide for the inclusion of novel drugs and molecular therapies into the standard chemoradiotherapy policy. Several studies have shown the prognostic importance of microvessel density (MVD) and of angiogenic factor expression in operable gastric cancer. In the present study we investigated, with immunohistochemistry the MVD, the expression of vascular endothelial growth factor (VEGF) and of thymidine phosphorylase (TP) expression, as well as the nuclear expression of p53 protein, in a series of patients with locally advanced inoperable gastric cancer. A strong association of VEGF with TP expression was noted (P = 0.005), and tumors coexpressing these factors had a statistically higher MVD (P = 0.0001). Nuclear p53 accumulation was also related to a high MVD (P = 0.004), and this was independent of VEGF or TP expression. Microvessel density showed a bell-shaped association with prognosis; cases with an intermediate MVD exhibit a favorable outcome (P < 0.05). A trend of nuclear TP expression to define a group of patients with poorer prognosis was noted (P = 0.06), while none of the remaining variables showed any significant association. The immunostaining results allowed the grouping of the angiogenic profile in four major categories: 1) highly vascularized tumors with VEGF and/or TP expression (about 36% of cases); 2) highly angiogenic tumors with p53 nuclear accumulation and low VEGF/TP expression (7% of cases); 3) poorly vascularized tumor with low VEGF/TP and negative nuclear p53 staining (32% of cases); 4) poorly vascularized tumors with TP expression (7% of cases). Specific therapies targeting hypoxia, VEGF, or TP expression as well as p53 gene therapy have entered clinical experimentation or are already available for clinical use. Using the suggested markers more than 80% of locally advanced gastric carcinomas can be grouped in different categories according to their angiogenic profile. Such a categorization may be useful for phase III trials on novel therapies targeting the major angiogenesis-related features studied here.

Hypoxia inducible factor (HIF-1a and HIF-2a) expression in early esophageal cancer and response to photodynamic therapy and radiotherapy

Hypoxia inducible factor 1a and 2a (HIF-1a and HIF-2a) are key proteins regulating cellular response to hypoxia. Because the efficacy of photodynamic therapy (PDT) is dependent on the presence of oxygen, the assessment of HIF-1a and HIF-2a expression may be of value in predicting clinical response to PDT. Using recently produced MoAbs, we examined the expression of HIF1a and HIF2a in a series of 37 early-stage esophageal cancers treated with PDT and with additional radiotherapy in case of incomplete response after PDT. Strong expression of the HIF1a and of HIF2a proteins in all optical fields examined was noted in 51% and in 13% of cases, respectively. High expression was associated with a low complete response (CR) rate and with the absence of bcl-2 protein expression. On the contrary, bcl-2 expression was associated with a high CR rate. Combined analysis of HIF1a and bcl-2 protein expression revealed that of 16 cases with high HIF1a expression and the absence of bcl-2 reactivity, only 1 (7%) responded completely to PDT (P = 0.007). Bivariate analysis showed that HIF1a expression was independently related to response to PDT (P = 0.04; t ratio = 2.8), whereas bcl-2 approached significance (P = 0.07; t-ratio = 1.8). The final response to radiotherapy was high (70%) and independent of the HIF and bcl-2 status, which may be a result of reoxygenation after cellular depletion mediated by PDT. The present study suggests that assessment of HIF and of bcl-2 expression are important predictors of in vivo sensitivity to PDT. Modulation of PDT response with bioreductive drugs and/or drugs targeting bcl-2 (i.e., taxanes) may prove of significant therapeutic importance in a subgroup of patients with high HIF expression.

'Invading edge vs. inner' (edvin) patterns of vascularization: an interplay between angiogenic and vascular survival factors defines the clinical behaviour of non-small cell lung cancer

Neo-angiogenesis during neoplastic growth involves endothelial mitogenic and migration stimuli produced by cancer or tumour stromal cells. Although this active angiogenesis takes place in the tumour periphery, the process of vessel growth and survival in inner areas and its clinical role remain largely unexplored. The present study compared the microvessel score (MS) as well as the single endothelial cell score (ECS) in the invading edge and in inner areas of non-small cell lung carcinomas (NSCLCs). Three different patterns of vascular growth were distinguished: the edvin (edge vs. inner) type 1, where a low MS was observed in both peripheral and inner tumour areas; the edvin type 2, where a high MS was noted in the invading front but a low MS in inner areas; and the edvin type 3, where both peripheral and inner tumour areas had a high MS. The ECS was high in the invading edge in edvin type 2 and 3 cases and was sharply decreased in both types in inner areas, suggesting that endothelial cell migration is unlikely to contribute to the angiogenic process in areas away from the tumour front. Expression of the vascular endothelial growth factor (VEGF) and of thymidine phosphorylase (TP) was associated with a high MS in the invading edge. VEGF was associated with a high MS in inner areas (edvin 3), while TP expression was associated with edvin type 2, showing that VEGF (and not TP) contributes to the preservation of the inner vasculature. Both edvin type 2 and 3 cases showed an increased incidence of node metastasis, but edvin type 3 cases had a poorer prognosis, even in the N1-stage group. The present study suggests that tumour factors regulating angiogenesis and vascular survival are not identical. A possible method is reported to quantify these two parameters by comparing the MS in the invading edge and inner areas (edvin types). This observation may contribute to the evaluation of the effectiveness of different therapeutic approaches, namely vascular targeting vs. anti-angiogenesis.

'Invading edge vs. inner' (edvin) patterns of vascularization: an interplay between angiogenic and vascular survival factors defines the clinical behaviour of non-small cell lung cancer

Neo-angiogenesis during neoplastic growth involves endothelial mitogenic and migration stimuli produced by cancer or tumour stromal cells. Although this active angiogenesis takes place in the tumour periphery, the process of vessel growth and survival in inner areas and its clinical role remain largely unexplored. The present study compared the microvessel score (MS) as well as the single endothelial cell score (ECS) in the invading edge and in inner areas of non-small cell lung carcinomas (NSCLCs). Three different patterns of vascular growth were distinguished: the edvin (edge vs. inner) type 1, where a low MS was observed in both peripheral and inner tumour areas; the edvin type 2, where a high MS was noted in the invading front but a low MS in inner areas; and the edvin type 3, where both peripheral and inner tumour areas had a high MS. The ECS was high in the invading edge in edvin type 2 and 3 cases and was sharply decreased in both types in inner areas, suggesting that endothelial cell migration is unlikely to contribute to the angiogenic process in areas away from the tumour front. Expression of the vascular endothelial growth factor (VEGF) and of thymidine phosphorylase (TP) was associated with a high MS in the invading edge. VEGF was associated with a high MS in inner areas (edvin 3), while TP expression was associated with edvin type 2, showing that VEGF (and not TP) contributes to the preservation of the inner vasculature. Both edvin type 2 and 3 cases showed an increased incidence of node metastasis, but edvin type 3 cases had a poorer prognosis, even in the N1-stage group. The present study suggests that tumour factors regulating angiogenesis and vascular survival are not identical. A possible method is reported to quantify these two parameters by comparing the MS in the invading edge and inner areas (edvin types). This observation may contribute to the evaluation of the effectiveness of different therapeutic approaches, namely vascular targeting vs. anti-angiogenesis.