Sir Peter MacCallum Department of Oncology - Research Publications

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    The transcription factor DEC1 (stra13, SHARP2) is associated with the hypoxic response and high tumour grade in human breast cancers
    Chakrabarti, J ; Turley, H ; Campo, L ; Han, C ; Harris, AL ; Gatter, KC ; Fox, SB (NATURE PUBLISHING GROUP, 2004-08-31)
    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)-1alpha and via HIF-1alpha, 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-1alpha (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.
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    Breast tumour angiogenesis
    Fox, SB ; Generali, DG ; Harris, AL (BMC, 2007)
    The central importance of tumour neovascularization has been emphasized by clinical trials using antiangiogenic therapy in breast cancer. This review gives a background to breast tumour neovascularization in in situ and invasive breast cancer, outlines the mechanisms by which this is achieved and discusses the influence of the microenvironment, focusing on hypoxia. The regulation of angiogenesis and the antivascular agents that are used in an antiangiogenic dosing schedule, both novel and conventional, are also summarized.
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    Relationship of vascular maturation in breast cancer blood vessels to vascular density and metastasis, assessed by expression of a novel basement membrane component, LH39
    Kakolyris, S ; Fox, SB ; Koukourakis, M ; Giatromanolaki, A ; Brown, N ; Leek, RD ; Taylor, M ; Leigh, IM ; Gatter, KC ; Harris, AL (CHURCHILL LIVINGSTONE, 2000-02)
    Angiogenesis, the formation of new vessels, has been demonstrated to be an indicator of prognosis in breast cancer patients. The extent of differentiation of the tumour vessels may affect access of peripheral white cells and egress or invasion of tumour cells. This has not been assessed in relation to tumour microvessel density or other variables and may be a marker of vascular remodelling. 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. To study vascular differentiation in breast tumours, we examined the vascular maturation index (VMI) in 12 normal and 50 breast carcinomas and this was correlated with different clinicopathological variables including angiogenesis. Mature vessels were defined by staining with antibodies to both LH39 and to CD31, using double immunohistochemistry, whereas immature vessels stained only for CD31. VMI was defined as the % fraction of mature vessels (LH39-positive) / total number of vessels (CD31-positive). The VMI was significantly higher in normal (54-68.5%; median 66.5%) than in tumours (0-47%; median 8.8%) (P = 0.0005). There was a significant inverse correlation between the tumour VMI and nodal status (Fisher's exact test, P = 0.01) and between high VMI and low thymidine phosphorylase (TP) expression (Mann-Whitney U-test, P= 0.01). No significant association between VMI and tumour size, oestrogen receptor, epidermal growth factor receptor, grade, angiogenesis, patient age, or E-selectin was seen. There was a significant reduction in relapse-free survival (P = 0.01) with high angiogenesis. These findings show that the VMI gives new information on the mechanism of tumour angiogenesis independently from microvessel quantitation, there is a wide variation in the differentiation of tumour vasculature but the degree of capillary differentiation is not associated with quantitative angiogenesis. The VMI identifies a subset of patients who have a high chance of regional node involvement.
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    Expression of delta-like ligand 4 (Dll4) and markers of hypoxia in colon cancer
    Jubb, AM ; Turley, H ; Moeller, HC ; Steers, G ; Han, C ; Li, J-L ; Leek, R ; Tan, EY ; Singh, B ; Mortensen, NJ ; Noguera-Troise, I ; Pezzella, F ; Gatter, KC ; Thurston, G ; Fox, SB ; Harris, AL (NATURE PUBLISHING GROUP, 2009-11-10)
    BACKGROUND: Delta-like ligand 4 (Dll4) is a Notch ligand that is upregulated by hypoxia and vascular endothelial growth factor-A (VEGF-A) and is reported to have a role in tumor angiogenesis. Evidence from xenograft studies suggests that inhibiting Dll4-Notch signalling may overcome resistance to anti-VEGF therapy. The aim of this study was to characterise the expression of Dll4 in colon cancer and to assess whether it is associated with markers of hypoxia and prognosis. METHOD: In all, 177 colon cancers were represented in tissue microarrays. Immunohistochemistry was performed using validated antibodies against Dll4, VEGF, hypoxia-inducible factor (HIF)-1alpha, HIF-2alpha, prolyl hydroxylase (PHD)1, PHD2, PHD3 and carbonic anhydrase 9 (CA9). RESULTS: The expression of Dll4 was observed preferentially in the endothelium of 71% (125 out of 175) of colon cancers, but not in the endothelium adjacent to normal mucosa (none out of 107, P<0.0001). The expression of VEGF was significantly associated with HIF-2alpha (P<0.0001) and Dll4 (P=0.010). Only HIF-2alpha had a significant multivariate prognostic effect (hazard ratio 1.61, 95% confidence interval 1.01-2.57). Delta-like ligand 4 was also expressed by neoplastic cells, particularly neoplastic goblet cells. CONCLUSION: Endothelial expression of Dll4 is not a prognostic factor, but is significantly associated with VEGF. Assessing endothelial Dll4 expression may be critical in predicting response to anti-VEGF therapies.
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    BRCA1 tumours correlate with a HIF-1α phenotype and have a poor prognosis through modulation of hydroxylase enzyme profile expression
    Yan, M ; Rayoo, M ; Takano, EA ; Thorne, H ; Fox, SB (NATURE PUBLISHING GROUP, 2009-09-29)
    BACKGROUND: There are limited data regarding the hypoxia pathway in familial breast cancers. We therefore performed a study of hypoxic factors in BRCA1, BRCA2 and BRCAX breast cancers. METHODS: Immunoperoxidase staining for HIF-1alpha, PHD1, PHD2, PHD3, VEGF and FIH was carried out in 125 (38 BRCA1, 33 BRCA2 and 54 BRCAX) breast carcinomas. These were correlated with clinicopathological parameters and the intrinsic breast cancer phenotypes. RESULTS: BRCA1 tumours correlated with positivity for HIF-1alpha (P=0.008) and negativity for PHD3 (P=0.037). HIF-1alpha positivity (P=0.001), PHD3 negativity (P=0.037) and nuclear FIH negativity (P=0.011) was associated with basal phenotype. HIF-1alpha expression correlated with high tumour grade (P=0.009), negative oestrogen receptor (ER) status (P=0.001) and the absence of lymph node metastasis (P=0.028). Nuclear FIH expression and PHD3 correlated with positive ER expression (P=0.024 and P=0.035, respectively). BRCA1 cancers with positive HIF-1alpha or cytoplasmic FIH had a significantly shorter relapse-free survival (P=0.007 and P=0.049, respectively). CONCLUSIONS: The aggressive nature of BRCA1 and basal-type tumours may be partly explained by an enhanced hypoxic drive and hypoxia driven ER degradation because of suppressed PHD and aberrantly located FIH expression. This may have important implications, as these tumours may respond to compounds directed against HIF-1alpha or its downstream targets.
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    Adrenomedullin and tumour angiogenesis
    Nikitenko, LL ; Fox, SB ; Kehoe, S ; Rees, MCP ; Bicknell, R (NATURE PUBLISHING GROUP, 2006-01-16)
    The angiogenic activity of peptide adrenomedullin (AM) was first shown in 1998 . Since then, a number of reports have confirmed the ability of AM to induce the growth and migration of isolated vascular endothelial and smooth muscle cells in vitro and to promote angiogenesis in xenografted tumours in vivo. In addition, knockout murine models point to an essential role for AM in embryonic vasculogenesis and ischaemic revascularisation. AM expression is upregulated by hypoxia (a typical feature of solid tumours) and a potential role as a regulator of carcinogenesis and tumour progression has been proposed based on studies in vitro and in animal models. Nevertheless, translational research on AM, and in particular, confirmation of its importance in the vascularisation of human tumours has lagged behind. In this commentary, we review current progress and potential directions for future research into the role of AM in tumour angiogenesis.
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    Inflammatory breast cancer shows angiogenesis with high endothelial proliferation rate and strong E-cadherin expression
    Colpaert, CG ; Vermeulen, PB ; Benoy, I ; Soubry, A ; Van Roy, F ; van Beest, P ; Goovaerts, G ; Dirix, LY ; Van Dam, P ; Fox, SB ; Harris, AL ; Van Marck, EA (NATURE PUBLISHING GROUP, 2003-03-10)
    Inflammatory breast cancer (IBC) is the most aggressive form of breast cancer. Improved understanding of the mechanisms responsible for the differences between IBC and non-IBC might provide novel therapeutic targets. We studied 35 consecutive patients with IBC, biopsied prior to the initiation of chemotherapy. Angiogenesis was evaluated by Chalkley counting and by assessment of endothelial cell proliferation (ECP) and vessel maturity. The presence of fibrin, expression of the hypoxia marker carbonic anhydrase IX (CA IX) and epithelialcadherin (E-cadherin) expression were immunohistochemically detected. The same parameters were obtained in a group of 104 non-IBC patients. Vascular density, assessed by Chalkley counting (P<0.0001), and ECP (P=0.01) were significantly higher in IBC than in non-IBC. Abundant stromal fibrin deposition was observed in 26% of IBC and in only 8% of non-IBC (P=0.02). Expression of CA IX was significantly less frequent in IBC than in non-IBC with early metastasis (P=0.047). There was a significant positive correlation between the expression of CA IX and ECP in IBC (r=0.4, P=0.03), implying that the angiogenesis is partly hypoxia driven. However, the higher ECP in IBC and the less frequent expression of CA IX in IBC vs non-IBC points at a role for other factors than hypoxia in stimulating angiogenesis. Strong, homogeneous E-cadherin expression was found at cell-cell contacts in all but two IBC cases, both in lymphovascular tumour emboli and in infiltrating tumour cells, challenging our current understanding of the metastatic process. Both the intense angiogenesis and the strong E-cadherin expression may contribute to the highly metastatic phenotype of IBC.
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    The key hypoxia regulated gene CAIX is upregulated in basal-like breast tumours and is associated with resistance to chemotherapy
    Tan, EY ; Yan, M ; Campo, L ; Han, C ; Takano, E ; Turley, H ; Candiloro, I ; Pezzella, F ; Gatter, KC ; Millar, EKA ; O'Toole, SA ; McNeil, CM ; Crea, P ; Segara, D ; Sutherland, RL ; Harris, AL ; Fox, SB (NATURE PUBLISHING GROUP, 2009-01-22)
    Basal-like tumours account for 15% of invasive breast carcinomas and are associated with a poorer prognosis and resistance to therapy. We hypothesised that this aggressive phenotype is because of an intrinsically elevated hypoxic response. Microarrayed tumours from 188 patients were stained for hypoxia-inducible factor (HIF)-1alpha, prolyl hydroxylase (PHD)1, PHD2, PHD3 and factor inhibiting HIF (FIH)-1, and carbonic anhydrase (CA) IX stained in 456 breast tumours. Tumour subtypes were correlated with standard clincopathological parameters as well as hypoxic markers. Out of 456 tumours 62 (14%) tumours were basal-like. These tumours were positively correlated with high tumour grade (P<0.001) and were associated with a significantly worse disease-free survival compared with luminal tumours (P<0.001). Fifty percent of basal-like tumours expressed HIF-1alpha, and more than half expressed at least one of the PHD enzymes and FIH-1. Basal-like tumours were nine times more likely to be associated with CAIX expression (P<0.001) in a multivariate analysis. Carbonic anhydrase IX expression was positively correlated with tumour size (P=0.005), tumour grade (P<0.001) and oestrogen receptor (ER) negativity (P<0.001). Patients with any CAIX-positive breast tumour phenotype and in the basal tumour group had a significantly worse prognosis than CAIX-negative tumours when treated with chemotherapy (P<0.001 and P=0.03, respectively). The association between basal phenotype and CAIX suggests that the more aggressive behaviour of these tumours is partly due to an enhanced hypoxic response. Further, the association with chemoresistance in CAIX-positive breast tumours and basal-like tumours in particular raises the possibility that targeted therapy against HIF pathway or downstream genes such as CAs may be an approach to investigate for these patients.
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    First international consensus on the methodology of lymphangiogenesis quantification in solid human tumours
    Van der Auwera, I ; Cao, Y ; Tille, JC ; Pepper, MS ; Jackson, DG ; Fox, SB ; Harris, AL ; Dirix, LY ; Vermeulen, PB (SPRINGERNATURE, 2006-12-18)
    The lymphatic system is the primary pathway of metastasis for most human cancers. Recent research efforts in studying lymphangiogenesis have suggested the existence of a relationship between lymphatic vessel density and patient survival. However, current methodology of lymphangiogenesis quantification is still characterised by high intra- and interobserver variability. For the amount of lymphatic vessels in a tumour to be a clinically useful parameter, a reliable quantification technique needs to be developed. With this consensus report, we therefore would like to initiate discussion on the standardisation of the immunohistochemical method for lymphangiogenesis assessment.
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    Detection of the transforming AKT1 mutation E17K in non-small cell lung cancer by high resolution melting.
    Do, H ; Solomon, B ; Mitchell, PL ; Fox, SB ; Dobrovic, A (Springer Science and Business Media LLC, 2008-05-16)
    BACKGROUND: A recurrent somatic mutation, E17K, in the pleckstrin homology domain of the AKT1 gene, has been recently described in breast, colorectal, and ovarian cancers. AKT1 is a pivotal mediator of signalling pathways involved in cell survival, proliferation and growth. The E17K mutation stimulates downstream signalling and exhibits transforming activity in vitro and in vivo. FINDINGS: We developed a sensitive high resolution melting (HRM) assay to detect the E17K mutation from formalin-fixed paraffin-embedded tumours. We screened 219 non-small cell lung cancer biopsies for the mutation using HRM analysis. Four samples were identified as HRM positive. Subsequent sequencing of those samples confirmed the E17K mutation in one of the cases. A rare single nucleotide polymorphism was detected in each of the remaining three samples. The E17K was found in one of the 14 squamous cell carcinomas. No mutations were found in 141 adenocarcinomas and 39 large cell carcinomas. CONCLUSION: The AKT1 E17K mutation is very rare in lung cancer and might be associated with tumorigenesis in squamous cell carcinoma. HRM represents a rapid cost-effective and robust screening of low frequency mutations such as AKT1 mutations in clinical samples.