Limits...
Efficient targeting of head and neck squamous cell carcinoma by systemic administration of a dual uPA and MMP-activated engineered anthrax toxin.

Schafer JM, Peters DE, Morley T, Liu S, Molinolo AA, Leppla SH, Bugge TH - PLoS ONE (2011)

Bottom Line: HNSCC is characterized by the upregulation of a large number of proteolytic enzymes, including urokinase plasminogen activator (uPA) and an assortment of matrix metalloproteinases (MMPs) that may be expressed by tumor cells, by tumor-supporting stromal cells or by both.We found that this toxin displayed strong systemic anti-tumor activity towards a variety of xenografted human HNSCC cell lines by inducing apoptotic and necrotic tumor cell death, and by impairing tumor cell proliferation and angiogenesis.This intercomplementing toxin warrants further investigation as an anti-HNSCC agent.

View Article: PubMed Central - PubMed

Affiliation: Oral and Pharyngeal Cancer Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, Maryland, United States of America.

ABSTRACT
Head and neck squamous cell carcinoma (HNSCC) is the sixth most common cancer worldwide. Although considerable progress has been made in elucidating the etiology of the disease, the prognosis for individuals diagnosed with HNSCC remains poor, underscoring the need for development of additional treatment modalities. HNSCC is characterized by the upregulation of a large number of proteolytic enzymes, including urokinase plasminogen activator (uPA) and an assortment of matrix metalloproteinases (MMPs) that may be expressed by tumor cells, by tumor-supporting stromal cells or by both. Here we explored the use of an intercomplementing anthrax toxin that requires combined cell surface uPA and MMP activities for cellular intoxication and specifically targets the ERK/MAPK pathway for the treatment of HNSCC. We found that this toxin displayed strong systemic anti-tumor activity towards a variety of xenografted human HNSCC cell lines by inducing apoptotic and necrotic tumor cell death, and by impairing tumor cell proliferation and angiogenesis. Interestingly, the human HNSCC cell lines were insensitive to the intercomplementing toxin when cultured ex vivo, suggesting that either the toxin targets the tumor-supporting stromal cell compartment or that the tumor cell requirement for ERK/MAPK signaling differs in vivo and ex vivo. This intercomplementing toxin warrants further investigation as an anti-HNSCC agent.

Show MeSH

Related in: MedlinePlus

Increased necrosis and apoptosis and decreased proliferation and vessel density of human HN12 xenografts in intercomplementing toxin-treated mice.Necrosis (A), proliferation (B), tumor vascularization (C), and apoptosis (D) of HN12 xenografts 5 days after initiation of systemic treatment with either PBS (blue bars and left panels) or intercomplementing toxin (red bars and right panels). A, hematoxylin and eosin staining. B, Ki67 staining. C, PECAM-1 staining. D, TUNEL staining. The arrows in D highlight examples of TUNEL positive cells. Columns, mean; bars, standard error of the mean, *, P<0.05. In all cases, representative images are shown. Scale Bars; 100 µM.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC3105081&req=5

pone-0020532-g003: Increased necrosis and apoptosis and decreased proliferation and vessel density of human HN12 xenografts in intercomplementing toxin-treated mice.Necrosis (A), proliferation (B), tumor vascularization (C), and apoptosis (D) of HN12 xenografts 5 days after initiation of systemic treatment with either PBS (blue bars and left panels) or intercomplementing toxin (red bars and right panels). A, hematoxylin and eosin staining. B, Ki67 staining. C, PECAM-1 staining. D, TUNEL staining. The arrows in D highlight examples of TUNEL positive cells. Columns, mean; bars, standard error of the mean, *, P<0.05. In all cases, representative images are shown. Scale Bars; 100 µM.

Mentions: We next examined the mechanistic basis for the potent systemic anti-HNSCC activity of the intercomplementing toxin. For this purpose HN12 (sensitive to intercomplementing toxin administered with FP59 in vitro) and Hep2 cells (insensitive to intercomplementing toxin administered with FP59 in vitro) were transplanted to mice, and established tumors were treated three times with toxin or PBS. The tumors were then excised (at day 5, as per Figure 2), and histological sections were generated, scanned, and subjected to an unbiased quantitative histomorphometric analysis. No tumor tissue was identified in histological sections from two of five examined HN12 toxin-treated tumors, indicating complete tumor regression. The three remaining toxin-treated HN12 tumors presented with a four-fold increase in the area of tumor necrosis, as compared to untreated tumors (Figure 3A). Cell proliferation in the remaining viable areas of these toxin-treated tumors was more than twelve-fold reduced, as determined by staining of the cell proliferation marker, Ki67 (Figure 3B). Vessel density was likewise reduced by three-fold (Figure 3C), while the apoptotic index was increased 13-fold (Figure 3D). Interestingly, unlike the case for the HN12 tumors examined above, the intercomplementing toxin primarily targeted Hep2 tumors by inducing necrosis (Figure 4). Thus, necrosis was increased by more than 13-fold (Figure 4A), while cell proliferation, vessel densities, and apoptotic indices in the remaining viable areas of the xenografted Hep2 tumors were all unaffected by treatment with intercomplementing toxin (Figure 4B-D). The retention of these latter tumor properties was notable given the striking decrease in tumor mass (Figure 2D, day 5).


Efficient targeting of head and neck squamous cell carcinoma by systemic administration of a dual uPA and MMP-activated engineered anthrax toxin.

Schafer JM, Peters DE, Morley T, Liu S, Molinolo AA, Leppla SH, Bugge TH - PLoS ONE (2011)

Increased necrosis and apoptosis and decreased proliferation and vessel density of human HN12 xenografts in intercomplementing toxin-treated mice.Necrosis (A), proliferation (B), tumor vascularization (C), and apoptosis (D) of HN12 xenografts 5 days after initiation of systemic treatment with either PBS (blue bars and left panels) or intercomplementing toxin (red bars and right panels). A, hematoxylin and eosin staining. B, Ki67 staining. C, PECAM-1 staining. D, TUNEL staining. The arrows in D highlight examples of TUNEL positive cells. Columns, mean; bars, standard error of the mean, *, P<0.05. In all cases, representative images are shown. Scale Bars; 100 µM.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3105081&req=5

pone-0020532-g003: Increased necrosis and apoptosis and decreased proliferation and vessel density of human HN12 xenografts in intercomplementing toxin-treated mice.Necrosis (A), proliferation (B), tumor vascularization (C), and apoptosis (D) of HN12 xenografts 5 days after initiation of systemic treatment with either PBS (blue bars and left panels) or intercomplementing toxin (red bars and right panels). A, hematoxylin and eosin staining. B, Ki67 staining. C, PECAM-1 staining. D, TUNEL staining. The arrows in D highlight examples of TUNEL positive cells. Columns, mean; bars, standard error of the mean, *, P<0.05. In all cases, representative images are shown. Scale Bars; 100 µM.
Mentions: We next examined the mechanistic basis for the potent systemic anti-HNSCC activity of the intercomplementing toxin. For this purpose HN12 (sensitive to intercomplementing toxin administered with FP59 in vitro) and Hep2 cells (insensitive to intercomplementing toxin administered with FP59 in vitro) were transplanted to mice, and established tumors were treated three times with toxin or PBS. The tumors were then excised (at day 5, as per Figure 2), and histological sections were generated, scanned, and subjected to an unbiased quantitative histomorphometric analysis. No tumor tissue was identified in histological sections from two of five examined HN12 toxin-treated tumors, indicating complete tumor regression. The three remaining toxin-treated HN12 tumors presented with a four-fold increase in the area of tumor necrosis, as compared to untreated tumors (Figure 3A). Cell proliferation in the remaining viable areas of these toxin-treated tumors was more than twelve-fold reduced, as determined by staining of the cell proliferation marker, Ki67 (Figure 3B). Vessel density was likewise reduced by three-fold (Figure 3C), while the apoptotic index was increased 13-fold (Figure 3D). Interestingly, unlike the case for the HN12 tumors examined above, the intercomplementing toxin primarily targeted Hep2 tumors by inducing necrosis (Figure 4). Thus, necrosis was increased by more than 13-fold (Figure 4A), while cell proliferation, vessel densities, and apoptotic indices in the remaining viable areas of the xenografted Hep2 tumors were all unaffected by treatment with intercomplementing toxin (Figure 4B-D). The retention of these latter tumor properties was notable given the striking decrease in tumor mass (Figure 2D, day 5).

Bottom Line: HNSCC is characterized by the upregulation of a large number of proteolytic enzymes, including urokinase plasminogen activator (uPA) and an assortment of matrix metalloproteinases (MMPs) that may be expressed by tumor cells, by tumor-supporting stromal cells or by both.We found that this toxin displayed strong systemic anti-tumor activity towards a variety of xenografted human HNSCC cell lines by inducing apoptotic and necrotic tumor cell death, and by impairing tumor cell proliferation and angiogenesis.This intercomplementing toxin warrants further investigation as an anti-HNSCC agent.

View Article: PubMed Central - PubMed

Affiliation: Oral and Pharyngeal Cancer Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, Maryland, United States of America.

ABSTRACT
Head and neck squamous cell carcinoma (HNSCC) is the sixth most common cancer worldwide. Although considerable progress has been made in elucidating the etiology of the disease, the prognosis for individuals diagnosed with HNSCC remains poor, underscoring the need for development of additional treatment modalities. HNSCC is characterized by the upregulation of a large number of proteolytic enzymes, including urokinase plasminogen activator (uPA) and an assortment of matrix metalloproteinases (MMPs) that may be expressed by tumor cells, by tumor-supporting stromal cells or by both. Here we explored the use of an intercomplementing anthrax toxin that requires combined cell surface uPA and MMP activities for cellular intoxication and specifically targets the ERK/MAPK pathway for the treatment of HNSCC. We found that this toxin displayed strong systemic anti-tumor activity towards a variety of xenografted human HNSCC cell lines by inducing apoptotic and necrotic tumor cell death, and by impairing tumor cell proliferation and angiogenesis. Interestingly, the human HNSCC cell lines were insensitive to the intercomplementing toxin when cultured ex vivo, suggesting that either the toxin targets the tumor-supporting stromal cell compartment or that the tumor cell requirement for ERK/MAPK signaling differs in vivo and ex vivo. This intercomplementing toxin warrants further investigation as an anti-HNSCC agent.

Show MeSH
Related in: MedlinePlus