Journal Article•
Modulation of Radiation Response after Epidermal Growth Factor Receptor Blockade in Squamous Cell Carcinomas: Inhibition of Damage Repair, Cell Cycle Kinetics, and Tumor Angiogenesis
01 Jun 2000-Clinical Cancer Research (American Association for Cancer Research)-Vol. 6, Iss: 6, pp 2166-2174
TL;DR: The collective data suggest that the profound in vivo antitumor activity identified in the xenograft setting when C225 is combined with radiation derives from more than simply the antiproliferative and cell cycle effects of EGFR system inhibition.
Abstract: We
have recently demonstrated that molecular blockade of the epidermal
growth factor receptor with the anti-epidermal growth factor receptor
(EGFR) monoclonal antibody C225 enhances the in vitro
radiosensitivity of human squamous cell carcinomas (SCCs) derived from
the head and neck. In the present study, we further investigated the
capacity of C225 to modulate the in vitro and in
vivo radiation response of human SCC tumor cells and
xenografts, and we examined several potential mechanisms that may
contribute to the enhanced radiation response induced by C225. Tumor
xenograft studies demonstrated complete regression of both newly
established (20 mm 3 ) and well-established (100
mm 3 ) SCC tumors over a 55–100 day follow-up period in
athymic mice treated with the combination of C225 (i.p. injection) and
radiation. Cell cycle analysis via flow cytometry confirmed that
combined treatment with C225 and radiation induced an accumulation of
cells in the more radiosensitive cell cycle phases (G 1 ,
G 2 -M) with concurrent reduction in the proportion of cells
in the more radioresistant S phase. Results from sublethal damage
repair and potentially lethal damage repair analyses in cultured SCC
cells demonstrated a strong inhibitory effect of C225 on postradiation
damage repair. Further, exposure of SCC cells to C225 induced a
redistribution of DNA-dependent protein kinase from the nucleus to the
cytosol, suggesting one potential mechanism whereby C225 may influence
the cellular response to radiation. Immunohistochemical analysis of SCC
tumor xenografts after systemic administration of C225 demonstrated
inhibition of the in vivo expression of tumor
angiogenesis markers, including vascular endothelial growth factor and
Factor VIII. Taken together, the collective data suggest that the
profound in vivo antitumor activity identified in the
xenograft setting when C225 is combined with radiation derives from
more than simply the antiproliferative and cell cycle effects of EGFR
system inhibition. In addition to antiproliferative growth inhibition,
EGFR blockade with C225 appears to influence the capacity of human SCCs
to effect DNA repair after exposure to radiation, and to express
classic markers of tumor angiogenesis.
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University of Alabama at Birmingham1, University of Wisconsin-Madison2, Autonomous University of Barcelona3, Eli Lilly and Company4, University of Texas MD Anderson Cancer Center5, University of Virginia6, University of the Witwatersrand7, University of Colorado Boulder8, Gdańsk Medical University9, University of Alabama10, Merck KGaA11, ImClone Systems12
TL;DR: Treatment of locoregionally advanced head and neck cancer with concomitant high-dose radiotherapy plus cetuximab improves locoreGional control and reduces mortality without increasing the common toxic effects associated with radiotherapy to the head andneck.
Abstract: BACKGROUND We conducted a multinational, randomized study to compare radiotherapy alone with radiotherapy plus cetuximab, a monoclonal antibody against the epidermal growth factor receptor, in the treatment of locoregionally advanced squamous-cell carcinoma of the head and neck. METHODS Patients with locoregionally advanced head and neck cancer were randomly assigned to treatment with high-dose radiotherapy alone (213 patients) or high-dose radiotherapy plus weekly cetuximab (211 patients) at an initial dose of 400 mg per square meter of body-surface area, followed by 250 mg per square meter weekly for the duration of radiotherapy. The primary end point was the duration of control of locoregional disease; secondary end points were overall survival, progression-free survival, the response rate, and safety. RESULTS The median duration of locoregional control was 24.4 months among patients treated with cetuximab plus radiotherapy and 14.9 months among those given radiotherapy alone (hazard ratio for locoregional progression or death, 0.68; P = 0.005). With a median follow-up of 54.0 months, the median duration of overall survival was 49.0 months among patients treated with combined therapy and 29.3 months among those treated with radiotherapy alone (hazard ratio for death, 0.74; P = 0.03). Radiotherapy plus cetuximab significantly prolonged progression-free survival (hazard ratio for disease progression or death, 0.70; P = 0.006). With the exception of acneiform rash and infusion reactions, the incidence of grade 3 or greater toxic effects, including mucositis, did not differ significantly between the two groups. CONCLUSIONS Treatment of locoregionally advanced head and neck cancer with concomitant highdose radiotherapy plus cetuximab improves locoregional control and reduces mortality without increasing the common toxic effects associated with radiotherapy to the head and neck. (ClinicalTrials.gov number, NCT00004227.)
4,705 citations
TL;DR: Cetuximab has clinically significant activity when given alone or in combination with irinotecan in patients with ir inotecans-refractory colorectal cancer.
Abstract: background The epidermal growth factor receptor (EGFR), which participates in signaling pathways that are deregulated in cancer cells, commonly appears on colorectal-cancer cells. Cetuximab is a monoclonal antibody that specifically blocks the EGFR. We compared the efficacy of cetuximab in combination with irinotecan with that of cetuximab alone in metastatic colorectal cancer that was refractory to treatment with irinotecan. methods We randomly assigned 329 patients whose disease had progressed during or within three months after treatment with an irinotecan-based regimen to receive either cetuximab and irinotecan (at the same dose and schedule as in a prestudy regimen [218 patients]) or cetuximab monotherapy (111 patients). In cases of disease progression, the addition of irinotecan to cetuximab monotherapy was permitted. The patients were evaluated radiologically for tumor response and were also evaluated for the time to tumor progression, survival, and side effects of treatment. results The rate of response in the combination-therapy group was significantly higher than that in the monotherapy group (22.9 percent [95 percent confidence interval, 17.5 to 29.1 percent] vs. 10.8 percent [95 percent confidence interval, 5.7 to 18.1 percent], P=0.007). The median time to progression was significantly greater in the combination-therapy group (4.1 vs. 1.5 months, P<0.001 by the log-rank test). The median survival time was 8.6 months in the combination-therapy group and 6.9 months in the monotherapy group (P=0.48). Toxic effects were more frequent in the combinationtherapy group, but their severity and incidence were similar to those that would be expected with irinotecan alone. conclusions Cetuximab has clinically significant activity when given alone or in combination with irinotecan in patients with irinotecan-refractory colorectal cancer.
4,625 citations
Journal Article•
TL;DR: This correlative study in a large series of patients revealed that EGFR expression, which varied considerably among HNSCCs, was a strong independent prognostic indicator for OS and DFS and a robust predictor for LR relapse but not for distant metastasis.
Abstract: A correlative study was performed to address the impact of epidermal growth factor receptor (EGFR) overexpression on survival and pattern of failure in patients with advanced head and neck squamous cell carcinomas (HNSCCs) enrolled in a Phase III trial and randomized to receive conventional radiotherapy. The study population comprised 155 of 268 (58%) randomized patients with sufficient pretreatment biopsy specimens for immunohistochemical assay. The specimens were dewaxed and incubated after standard preparation with mouse monoclonal antibodies recognizing the extracellular domain of the EGFR molecule. The catalyzed product was visualized with 3,3'-diaminobenzidine Chromogen Kit and lightly counterstained with Mayer's hematoxylin. Quantitative EGFR immunohistochemistry (IHC) was done with SAMBA 4000 Cell Image Analysis System, without knowledge of the clinical outcome, to yield mean absorbance (MOD), staining index (SI), and quick score (QS). These EGFR IHC parameters were correlated with the T stage, N stage, combined stage grouping, and recursive partitioning analysis classes. Subsequently, the EGFR parameters were correlated with the outcome end points, i.e., overall survival (OS), disease-free survival (DFS), local-regional (LR) relapse, and distant metastasis rates. We found that HNSCCs exhibited a wide variation in EGFR expression (MOD, 0.2-66.0; SI, 0.3-97.0; QS, 0.01-69.9) with a relatively strong but nonlinear correlation between MOD and SI (r = 0.79). There was no correlation between EGFR expression and T stage, N stage, stage grouping, and recursive partitioning analysis classes (r = -0.07 to 0.17). The OS and DFS rates of patients with high EGFR-expressing HNSCCs (>median MOD) were highly significantly lower (P = 0.0006 and P = 0.0016, respectively) and the LR relapse rate was highly significantly higher (P = 0.0031) compared with those of patients with low EGFR-expressing HNSCCs. However, there was no difference in the distant metastasis rate between the two groups (P = 0.96). Significant correlations, although somewhat less robust than MOD, were also observed between SI and QS and the OS, DFS, and LR relapse rates. Multivariate analysis showed that EGFR expression was an independent determinant of survival and a robust independent predictor of LR relapse. In summary, this correlative study in a large series of patients revealed that EGFR expression, which varied considerably among HNSCCs, was a strong independent prognostic indicator for OS and DFS and a robust predictor for LR relapse but not for distant metastasis. The data suggest that EGFR IHC should be considered for selecting patients for more aggressive combined therapies or enrollment into trials targeting EGFR signaling pathways.
1,171 citations
Cites background from "Modulation of Radiation Response af..."
...Another study revealed that EGFR blockade leads to redistribution of DNA-PK from the nucleus to the cytosol, resulting in reduced radiation-induced DNA damage repair and thus radiation sensitization, detectable through the classical split-dose experiment (19)....
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Journal Article•
TL;DR: A mini-review describes the EGFR inhibitors in clinical development and preliminary results from Phase I and II trials in patients with advanced disease demonstrate that ZD1839 and OSI-774 have an acceptable tolerability profile and promising clinical efficacy in Patients with a variety of tumor types.
Abstract: The epidermal growth factor receptor (EGFR) autocrine pathway contributes to a number of processes important to cancer development and progression, including cell proliferation, apoptosis, angiogenesis, and metastatic spread. The critical role the EGFR plays in cancer has led to an extensive search for selective inhibitors of the EGFR signaling pathway. The results of a large body of preclinical studies and the early clinical trials thus far conducted suggest that targeting the EGFR could represent a significant contribution to cancer therapy. A variety of different approaches are currently being used to target the EGFR. The most promising strategies in clinical development include monoclonal antibodies to prevent ligand binding and small molecule inhibitors of the tyrosine kinase enzymatic activity to inhibit autophosphorylation and downstream intracellular signaling. At least five blocking monoclonal antibodies have been developed against the EGFR. Among these, IMC-225 is a chimeric human-mouse monoclonal IgG1 antibody that has been the first anti-EGFR targeted therapy to enter clinical evaluation in cancer patients in Phase II and III studies, alone or in combination with conventional therapies, such as radiotherapy and chemotherapy. A number of small molecule inhibitors of the EGFR tyrosine kinase enzymatic activity is also in development. OSI-774 and ZD1839 (Iressa) are currently in Phase II and III development, respectively. ZD1839, a p.o. active, selective quinazoline derivative has demonstrated promising in vitro and in vivo antitumor activity. Preliminary results from Phase I and II trials in patients with advanced disease demonstrate that ZD1839 and OSI-774 have an acceptable tolerability profile and promising clinical efficacy in patients with a variety of tumor types. This mini-review describes the EGFR inhibitors in clinical development.
1,010 citations
Cites background from "Modulation of Radiation Response af..."
...Among the potential mechanisms that contribute to the increased radiation sensitivity by treatment with IMCC225, various studies have suggested an accumulation of cancer cells in the more radiosensitive cell cycle phases (G1, G2-M), a blockade of radiation-induced DNA repair mechanisms, and a reduction of VEGF production by cancer cells with inhibition of tumor angiogenesis (33, 34, 36)....
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TL;DR: Growing evidence suggests that HIF-, mTOR- and UPR-dependent responses to hypoxia act in an integrated way, influencing each other and common downstream pathways that affect gene expression, metabolism, cell survival, tumorigenesis and tumour growth.
Abstract: Hypoxia occurs in the majority of tumours, promoting angiogenesis, metastasis and resistance to therapy. Responses to hypoxia are orchestrated in part through activation of the hypoxia-inducible factor family of transcription factors (HIFs). Recently, two additional O(2)-sensitive signalling pathways have also been implicated: signalling through the mammalian target of rapamycin (mTOR) kinase and signalling through activation of the unfolded protein response (UPR). Although they are activated independently, growing evidence suggests that HIF-, mTOR- and UPR-dependent responses to hypoxia act in an integrated way, influencing each other and common downstream pathways that affect gene expression, metabolism, cell survival, tumorigenesis and tumour growth.
835 citations
References
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TL;DR: The principles and practice of radiation oncology are studied in detail in a systematic manner in the context of cancer diagnosis and treatment.
Abstract: Principles and practice of radiation oncology , Principles and practice of radiation oncology , کتابخانه دیجیتال جندی شاپور اهواز
2,011 citations
Journal Article•
TL;DR: Therapeutic disruption of EGFR or ErbB2/neu protein function in vivo may result in partial suppression of angiogenesis, a feature that could enhance the therapeutic index of such agents in vivo and endow them with anti-tumor effects, the magnitude of which may be out of proportion with their observed cytostatic effects in monolayer tissue culture.
Abstract: The overexpression in tumor cells of (proto)-oncogenic receptor tyrosine kinases such as epidermal growth factor receptor (EGFR) or ErbB2/neu (also known as HER-2) is generally thought to contribute to the development of solid tumors primarily through their effects on promoting uncontrolled cell proliferation. However, agents that antagonize the function of the protein products encoded by these (proto)-oncogenes are known to behave in vivo in a cytotoxic-like manner. This implies that such oncogenes may regulate critical cell survival functions, including angiogenesis. The latter could occur as a consequence of regulation of relevant growth factors by such oncogenes. We therefore sought to determine whether EGFR or ErbB2/neu may contribute to tumor angiogenesis by examining their effects on the expression of vascular endothelial cell growth factor (VEGF)/vascular permeability factor (VPF), one of the most important of all known inducers of tumor angiogenesis. We found that in vitro treatment of EGFR-positive A431 human epidermoid carcinoma cells, which are known to be heavily dependent on VEGF/VPF in vivo as an angiogenesis growth factor, with the C225 anti-EGFR neutralizing antibody caused a dose-dependent inhibition of VEGF protein expression. Prominent suppression of VEGF/VPF expression in vivo, as well as a significant reduction in tumor blood vessel counts, were also observed in established A431 tumors shortly after injection of the antibody as few as four times into nude mice. Transformation of NIH 3T3 fibroblasts with mutant ErbB2/neu, another EGFR-like oncogenic tyrosine kinase, resulted in a significant induction of VEGF/VPF, and the magnitude of this effect was further elevated by hypoxia. Moreover, treatment of ErbB2/neu-positive SKBR-3 human breast cancer cells in vitro with a specific neutralizing anti-ErbB2/neu monoclonal antibody (4D5) resulted in a dose-dependent reduction of VEGF/VPF protein expression. Taken together, the results suggest that oncogenic properties of EGFR and ErbB2/neu may, at least in part, be mediated by stimulation of tumor angiogenesis by up-regulating potent angiogenesis growth factors such as VEGF/VPF. These genetic changes may cooperate with epigenetic/environmental effects such as hypoxia to maximally stimulate VEGF/VPF expression. Therapeutic disruption of EGFR or ErbB2/neu protein function in vivo may therefore result in partial suppression of angiogenesis, a feature that could enhance the therapeutic index of such agents in vivo and endow them with anti-tumor effects, the magnitude of which may be out of proportion with their observed cytostatic effects in monolayer tissue culture.
881 citations
"Modulation of Radiation Response af..." refers background in this paper
...Indeed, several recent associations between the EGFR pathway and tumor angiogenesis have been identified (12, 29, 30)....
[...]
Journal Article•
TL;DR: Examination of C225 effects on radiation response in SCCs demonstrates enhancement in radiosensitivity and amplification of radiation-induced apoptosis, and C225 represents a promising growth-inhibitory agent that can influence cellular proliferation, apoptosis and radiosensitivity in S CCs of the head and neck.
Abstract: We examined effects of the anti-epidermal growth factor receptor monoclonal antibody C225 on proliferation, cell cycle phase distribution, apoptosis, and radiosensitivity in squamous cell carcinoma (SCC) cell lines derived from head and neck cancer patients Exposure to C225 in culture inhibits SCC proliferation in a time-dependent manner, and the degree of growth inhibition, compared to controls, ranges from 20 to 75% Flow cytometry analysis demonstrates that C225 treatment induces accumulation of cells in G1, which is accompanied by a 2-3-fold decrease in the percentage of cells in S phase C225 exposure also induces apoptosis in SCC populations, as demonstrated by flow cytometry analysis using dual stainings of merocyanine 540 and Hoechst 33342 Western blot analysis indicates that C225 exposure induces accumulation of hypophosphorylated retinoblastoma protein and increases expression of p27KIP1 An increase in Bax expression and concurrent decrease in Bcl-2 expression are observed when SCC cells are exposed to C225 Examination of C225 effects on radiation response in SCCs demonstrates enhancement in radiosensitivity and amplification of radiation-induced apoptosis These effects are observed in both single-dose and fractionated radiation experiments C225 represents a promising growth-inhibitory agent that can influence cellular proliferation, apoptosis, and radiosensitivity in SCCs of the head and neck
723 citations
"Modulation of Radiation Response af..." refers background in this paper
...Previous work has demonstrated C225 to be a potent antiproliferative agent capable of inhibiting SCC cell growth in culture (6)....
[...]
...In addition, preclinical studies have demonstrated the capacity of C225 to enhance in vitro radiosensitivity and to promote radiation-induced apoptosis (6)....
[...]
...blockade of the epidermal growth factor receptor with the anti-epidermal growth factor receptor (EGFR) monoclonal antibody C225 enhances the in vitro radiosensitivity of human squamous cell carcinomas (SCCs) derived from the head and neck....
[...]
...In addition to antiproliferative growth inhibition, EGFR blockade with C225 appears to influence the capacity of human SCCs to effect DNA repair after exposure to radiation, and to express classic markers of tumor angiogenesis....
[...]
...Taken together, these results suggest that C225 compromises the capacity of SCCs to accomplish effective repair after radiation-induced damage....
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TL;DR: The results show an antitumour interaction between ionizing radiation and angiostatin for four distinct tumour types, at doses of radiation that are used in radiotherapy.
Abstract: Angiogenesis, the formation of new capillaries from pre-existing vessels, is essential for tumour progression1,2,3,4,5. Angiostatin, a proteolytic fragment of plasminogen6 that was first isolated from the serum and urine of tumour-bearing mice7, inhibits angiogenesis and thereby growth of primary8 and metastatic7,9,10 tumours. Radiotherapy is important in the treatment of many human cancers, but is often unsuccessful because of tumour cell radiation resistance11,12. Here we combine radiation with angiostatin to target tumour vasculature that is genetically stable and therefore less likely to develop resistance13,14,15. The results show an antitumour interaction between ionizing radiation and angiostatin for four distinct tumour types, at doses of radiation that are used in radiotherapy. The combination produced no increase in toxicity towards normal tissue. In vitro studies show that radiation and angiostatin have combined cytotoxic effects on endothelial cells, but not tumour cells. In vivo studies show that these agents, in combination, target the tumour vasculature. Our results provide support for combining ionizing radiation with angiostatin to improve tumour eradication without increasing deleterious effects.
696 citations
"Modulation of Radiation Response af..." refers background in this paper
...Recent findings suggest that the use of an angiogenesis inhibitor (angiostatin) during radiation therapy can significantly enhance response in human tumor xenografts (28)....
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Journal Article•
TL;DR: Therapy with anti-EGFR MAb C225 has a significant antitumor effect mediated, in part, by inhibition of angiogenesis, and down-regulation of these angiogenic factors preceded the involution of blood vessels.
Abstract: Epidermal growth factor receptor (EGFR) regulates the growth and progression of human transitional cell carcinoma (TCC) of the bladder. We have shown that therapy targeting EGFR inhibited the growth of human TCC established orthotopically in nude mice. The purpose of this study was to evaluate whether EGFR-directed therapy affects angiogenesis associated with the growth and metastasis of human TCC. We determined the cytostatic effect and the effect on production of angiogenic factors after in vitro treatment of the human TCC cell line 253J B-V with MAb C225, a chimerized monoclonal anti-EGFR antibody. The 253J B-V cells were implanted orthotopically into athymic nude mice, and established tumors (4 weeks) were treated with i.p. MAb C225. Expression of the angiogenic factors vascular endothelial growth factor (VEGF), interleukin-8 (IL-8), and basic fibroblast growth factor (bFGF) was evaluated by immunohistochemistry and in situ mRNA hybridization analyses and correlated with microvessel density evaluated after immunohistochemical staining with anti-CD31. In vitro treatment with MAb C225 inhibited mRNA and protein production of VEGF, IL-8, and bFGF by 253J B-V cells in a dose-dependent manner. MAb C225 therapy of nude mice with established TCCs growing orthotopically resulted in inhibition of growth and metastasis compared with controls (P <0.0005). VEGF, IL-8, and bFGF expression was significantly lower in treated tumors than in controls. The down-regulation of these angiogenic factors preceded the involution of blood vessels. These studies indicate that therapy with anti-EGFR MAb C225 has a significant antitumor effect mediated, in part, by inhibition of angiogenesis.
589 citations