umu.sePublications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Bacterial toxins for cancer treatment
Umeå University, Faculty of Medicine, Medical Biosciences.
2008 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Even though anti‐cancer chemotherapy has been continuously improved during the last decades. problems with adverse effects and drug resistance still constitutes a considerable obstacle and sets a demand for new effective treatment options. Tissue homeostasis in multi‐cellular organisms is maintained through intrinsic cell death, apoptosis, which removes unwanted or damaged cells. Disrupted apoptosis is an important factor in tumorgenesis and drug resistance, therefore induction or restoration of apoptotic pathways is also important for the treatment of cancer. Several naturally occurring bacterial toxins have the ability to induce apoptosis and could thus be candidates to complement or improve the therapeutic effect of other anticancer drugs.

The bacterial toxins, adenylate cyclase (AC) toxin from Bordetella pertussis, α‐toxin from Staphylococcus aureus and verotoxin‐1 (VT‐1) from Escherichia coli were investigated for their ability to induce apoptosis in different tumor cell lines. Toxin induction of cell death was investigated by cell viability assays, end‐stage apoptosis induction by DNA‐fregmentation (TUNEL) assay. Toxin receptor expression and signal transduction pathways to apoptosis were investigated by flow cytometry, caspase enzyme activity assays and western blot. Immunohistochemistry was used for identification of toxin receptor expression in tumor tissue samples.

AC‐toxin was cytotoxic and induced apoptosis in cultured malignant plural mesothelioma (MPM) and small‐cell lung cancer (SCLC) cells. Low‐toxic concentrations of AC‐toxin enhanced cisplatin cytotoxicity and apoptosis in both cell lines.

MPM‐cells with acquired cisplatin resistance were more sensitive to α‐toxin than the less resistant parental MPM cell line. A low‐toxic concentration of α‐toxin re‐sensitized resistant MPM cells to cisplatin cytotoxicity by apoptosis induced through the mitochondrial pathway without detectable activation of common up‐stream apoptosis signalling proteins.

VT‐1 was highly cytotoxic and induced apoptosis in globotriosylceramide (Gb3) ‐expressing glioma, breast cancer and non‐small‐cell lung cancer (NSCLC) cells but was not cytotoxic to non‐Gb3‐expressing cells. PPMP, an inhibitor of glucosylceramide synthesis which makes exposed cells unable to synthesize Gb3 rendered Gb3‐expressing cells resistant to VT‐1. MPM cells with acquired‐cisplatin resistance expressed Gb3 in contrast to the absent of expression in the less resistant parental cell line. Gb3, could however be up‐regulated by cisplatin in Gb3‐negative MPM‐cells. Presence of a low‐toxic concentration of VT‐1 potentiated cisplatin‐induced cytotoxicity and apoptosis in the cisplatin‐resistance MPM cell line. VT‐1 was a potent inducer of apoptosis, probably via stress‐induced Mitogen‐activated protein kinase (MAPK)‐signaling involving c‐Jun N‐terminal kinase (JNK) and p38, leading to disruption of the mitochondrial membrane integrety, activation of caspase‐9 and ‐3, and ultimately DNA fragmentation and cell death. Gb3 expression was demonstrated in clinical specimens of glioblastoma and breast cancer making these tumor types interesting for further VT‐1 studies.

We conclude that bacterial toxins may be used to induce apoptosis in several types of cancer cells. Low concentrations of verotoxin‐1 and α‐toxin may potentially be used to overcome acquired cisplatin‐resistance in cancer patients.

Place, publisher, year, edition, pages
Umeå: Medicinsk biovetenskap , 2008. , 47 p.
Series
Umeå University medical dissertations, ISSN 0346-6612 ; 1178
Keyword [en]
Alpha‐toxin, AC‐toxin, mesothelioma, lung cancer, glioma, breast cancer, caspases, MAP-Kinase, verotoxin‐1, cisplatin, apoptosis, Gb3, drug resistance
National Category
Other Clinical Medicine
Identifiers
URN: urn:nbn:se:umu:diva-1637ISBN: 978-91-7264-566-0 (print)OAI: oai:DiVA.org:umu-1637DiVA: diva2:141641
Public defence
2008-05-23, Sal D, 1D, 9 trappor, Norrlands universitetssjukhus, Umeå, 13:00 (English)
Opponent
Supervisors
Available from: 2008-05-05 Created: 2008-05-05 Last updated: 2010-01-21Bibliographically approved
List of papers
1. Adenylate cyclase toxin from Bordetella pertussis enhances cisplatin-induced apoptosis to lung cancer cells in vitro.
Open this publication in new window or tab >>Adenylate cyclase toxin from Bordetella pertussis enhances cisplatin-induced apoptosis to lung cancer cells in vitro.
Show others...
2006 (English)In: Oncology Research, ISSN 0965-0407, Vol. 15, no 9, 423-430 p.Article in journal (Refereed) Published
Abstract [en]

The present study examined the possibility to enhance lung cancer cell cytotoxicity and apoptosis of the anticancer drug cisplatin by exposure with adenylate cyclase (AC) toxin from Bordetella pertussis. A malignant mesothelioma cell line (P31) and a small-cell lung cancer cell line (U1690) were exposed to increasing concentrations of cisplatin and AC toxin, alone or in combination. Cytotoxicity was determined by a fluorescein-based assay and apoptosis by flow cytometry quantification of annexin V binding. Caspase-3, -8, and -9 activities were measured by enzyme activity assays. The cytotoxicity of AC toxin was time and dose dependent with an LD50 value at 72 h of 3 and 7 mg/L for P31 cells and U1690 cells, respectively. Cisplatin showed a similar time- and dose-dependent cytotoxicity, which was increased in the presence of a low toxic concentration (1 mg/L) of AC toxin. Furthermore, cisplatin caused a dose-dependent increase of annexin V binding cells of both cell lines after 24-h incubation, which was also enhanced in combination with AC toxin. AC toxin (1 mg/L) increased cisplatin-induced caspase-3, -8, and -9 activities in U1690 cells. Only minor increases of caspase-8 and -9 were noted for P31 cells. The present results, together with the knowledge that bacterial toxins decrease side effects of traditional cancer treatment, suggest a possibility to use them to enhance the therapeutic effect of cancer chemotherapy with reduced clinical adverse effects.

Keyword
Adenylate cyclase toxin, apoptosis, cisplatin, cytotoxicity, mesothelioma, small-cell lung cancer
Identifiers
urn:nbn:se:umu:diva-13678 (URN)16555548 (PubMedID)
Available from: 2007-12-13 Created: 2007-12-13 Last updated: 2011-07-05Bibliographically approved
2. alpha-Toxin of Staphylococcus aureus overcomes acquired cisplatin-resistance in malignant mesothelioma cells.
Open this publication in new window or tab >>alpha-Toxin of Staphylococcus aureus overcomes acquired cisplatin-resistance in malignant mesothelioma cells.
2008 (English)In: Cancer Letters, ISSN 0304-3835, E-ISSN 1872-7980, Vol. 265, no 1, 67-75 p.Article in journal (Refereed) Published
Abstract [en]

alpha-Toxin (alpha-hemolysin) of Staphylococcus aureus is a pore-forming bacterial toxin which after caveolin-1-dependent assembly induces apoptosis in eukaryotic cells. We investigated if a sub-toxic concentration of staphylococcal alpha-toxin could enhance cisplatin-induced apoptosis and overcome acquired cisplatin-resistance in cultured malignant pleural mesothelioma (MPM) cells. MPM cells (P31wt) and a cisplatin-resistant sub-line (P31res) was incubated with alpha-toxin and/or cisplatin followed by determination of cell viability, apoptosis, and signaling pathways. P31res cells were more sensitive to alpha-toxin than P31 wt cells due to induction of apoptosis. A low-toxic concentration of alpha-toxin re-sensitized cisplatin P31res cytotoxicity by apoptosis-induced through the mitochondrial pathway without detectable activation of common up-stream apoptosis signaling proteins. The toxin/drug combination should be tested for cisplatin-resistant mesothelioma treatment.

Identifiers
urn:nbn:se:umu:diva-22902 (URN)10.1016/j.canlet.2008.02.007 (DOI)18362050 (PubMedID)
Available from: 2009-05-19 Created: 2009-05-19 Last updated: 2017-12-13
3. Verotoxin-1 Induction of Apoptosis in Gb3-Expressing Human Glioma Cell Lines
Open this publication in new window or tab >>Verotoxin-1 Induction of Apoptosis in Gb3-Expressing Human Glioma Cell Lines
Show others...
2006 (English)In: Cancer Biology & Therapy, ISSN 1538-4047, Vol. 5, no 9, 1211-1217 p.Article in journal (Refereed) Published
Abstract [en]

The aim of this study was to examine the cytotoxicity and mechanism of apoptosis induction of verotoxin-1 (VT-1) in human glioma cell lines. VT-1 is a member of the shiga-toxin family expressed by some serotypes of Escherichia coli and Shigella dysenteriae. Shiga-toxins have been shown to induce apoptosis by binding to its membrane receptor Gb3. The human glioma cell lines SF-767, U-343 MG, and U-251 MG were studied together with BT4C, a rat glioma cell line. Cells were first screened for Gb3 expression by flow cytometry. Fluorescein diacetate was used to determine cell viability after VT-1 and irradiation exposure and apoptosis was studied by TUNEL staining, a mitochondrial membrane potential assay, and caspase activity assays. SF-767 and U-343 MG cells were found to express Gb3 and were also sensitive to VT-1-induced cytotoxicity, whereas nonGb3-expressing U-251 MG and BT4C glioma cells were not. VT-1 depolarized the mitochondrial membrane and activated caspase-9 and -3 of SF-767 and U-343 MG cells. VT-1 exposure for 72 h resulted in approx. 60 and 90% TUNEL-stained cells, respectively. D, L-Threo-1-phenyl-2-palmitoylamino-3-morpholino-1-propanol (PPMP) an inhibitor of glucosylceramide synthesis was used to block Gb3 synthesis. Two mumol/L PPMP for 72 h abolished SF-767 and U-343 MG expression of Gb3 and made the cells completely resistant to VT-1 induced apoptosis. Key components of MAP kinase signalling pathways that control BAX and mitochondrial function were investigated. VT-1 induced JNK phosphorylation in both cell lines, suggesting that survival signal pathways were overruled by VT-1-induced JNK activation leading to mitochondrial depolarization, caspase-9 activation and apoptosis. Immunohistochemistry of cryostat section from glioma biopsies demonstrated expression of Gb3 was in the vascular endothelial cells as well as tumor cells, but not in astrocytes. The high specificity and apoptosis inducing properties of verotoxin-1 indicates that the toxin may be a potential anti-neoplastic agent for Gb3-expressing gliomas.

Keyword
Apoptosis, Gb3, glioblastoma, MAP kinases, PPMP, Verotoxin-1
Identifiers
urn:nbn:se:umu:diva-13689 (URN)16929170 (PubMedID)
Available from: 2008-01-11 Created: 2008-01-11 Last updated: 2011-07-05Bibliographically approved
4. Expression of verotoxin‐1 receptor Gb3 in breast cancer
Open this publication in new window or tab >>Expression of verotoxin‐1 receptor Gb3 in breast cancer
Show others...
Manuscript (Other academic)
Identifiers
urn:nbn:se:umu:diva-3154 (URN)
Available from: 2008-05-05 Created: 2008-05-05 Last updated: 2010-01-13Bibliographically approved
5. Cisplatin-induced expression of Gb3 enables verotoxin-1 treatment of cisplatin resistance in malignant pleural mesothelioma cells
Open this publication in new window or tab >>Cisplatin-induced expression of Gb3 enables verotoxin-1 treatment of cisplatin resistance in malignant pleural mesothelioma cells
Show others...
2010 (English)In: British Journal of Cancer, ISSN 0007-0920, E-ISSN 1532-1827, Vol. 102, no 2, 383-391 p.Article in journal (Refereed) Published
Abstract [en]

Background:

A major problem with cisplatin treatment is the development of acquired-drug resistance of the tumour cells. Verotoxin-1 (VT-1) exerts its cytotoxicity by targeting the membrane glycolipid globotriasosylceramide (Gb3), a molecule associated with drug resistance. Cisplatin- and VT-1-induced apoptosis involves mitogen-activated protein kinase (MAPK) activation, and deactivation of MAPKs is associated with cisplatin resistance. This study aimed to investigate whether a sub-toxic concentration of VT-1 could enhance cisplatin-induced apoptosis and overcome acquired-cisplatin resistance in cultured cancer cell lines.

Method:

P31 and H1299 cells with corresponding cisplatin-resistant sub-lines (P31res/H1299res) were incubated with VT-1 and/or cisplatin followed by determination of Gb3 expression, cell viability, apoptosis, and signalling pathways.

Results:

Cells from the resistant sub-lines had elevated Gb3 expression compared with the parental cell lines, and cisplatin further increased Gb3 expression, whereas VT-1 reduced the percentage of Gb3-expressing cells. Combination of cisplatin and sub-toxic concentrations of VT-1 led to a super-additive increase of cytotoxicity and TUNEL staining, especially in the cisplatin-resistant sub-lines. Blockade of Gb3 synthesis by a Gb3 synthesis inhibitor not only led to eradicated TUNEL staining of P31 cells, but also sensitised P31res cells to the induction of apoptosis by cisplatin alone. Cisplatin- and VT-1-induced apoptosis involved the MAPK pathways with increased C-Jun N-terminal kinase and MAPK kinase-3 and -6 phosphorylation.

Conclusions:

We show the presence of Gb3 in acquired-cisplatin resistance in P31res and H1299res cells. Cisplatin up-regulated Gb3 expression in all cells and thus sensitised the cells to VT-1-induced cytotoxicity. A strong super-additive effect of combined cisplatin and a sub-toxic concentration of VT-1 in cisplatin-resistant malignant pleural mesothelioma cells were observed, indicating a new potential clinical-treatment approach.

Place, publisher, year, edition, pages
Nature Publishing Group, 2010
Keyword
acquired resistance, apoptosis, cisplatin, Gb3, mesothelioma, verotoxin-1
Identifiers
urn:nbn:se:umu:diva-3155 (URN)10.1038/sj.bjc.6605467 (DOI)000273728500019 ()
Available from: 2008-05-05 Created: 2008-05-05 Last updated: 2011-03-21Bibliographically approved

Open Access in DiVA

fulltext(1401 kB)1175 downloads
File information
File name FULLTEXT01.pdfFile size 1401 kBChecksum SHA-1
79c3a8a26c56a234a0371a473125e2c380f972802765f57bbe220afee8506f2e370d0741
Type fulltextMimetype application/pdf

By organisation
Medical Biosciences
Other Clinical Medicine

Search outside of DiVA

GoogleGoogle Scholar
Total: 1175 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

isbn
urn-nbn

Altmetric score

isbn
urn-nbn
Total: 1113 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf