Theiler’s murine encephalomyelitis virus infection induces a redistribution of heat shock proteins 70 and 90 in BHK-21 cells, and is inhibited by novobiocin and geldanamycin:
- Mutsvunguma, Lorraine Z, Moetlhoa, Boitumelo, Edkins, Adrienne L, Luke, Garry A, Blatch, Gregory L, Knox, Caroline M
- Authors: Mutsvunguma, Lorraine Z , Moetlhoa, Boitumelo , Edkins, Adrienne L , Luke, Garry A , Blatch, Gregory L , Knox, Caroline M
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/165085 , vital:41207 , DOI: 10.1007/s12192-011-0262-x
- Description: Theiler’s murine encephalomyelitis virus (TMEV) is a positive-sense RNA virus belonging to the Cardiovirus genus in the family Picornaviridae. In addition to other host cellular factors and pathways, picornaviruses utilise heat shock proteins (Hsps) to facilitate their propagation in cells. This study investigated the localisation of Hsps 70 and 90 in TMEV-infected BHK-21 cells by indirect immunofluorescence and confocal microscopy. The effect of Hsp90 inhibitors novobiocin (Nov) and geldanamycin (GA) on the development of cytopathic effect (CPE) induced by infection was also examined. Hsp90 staining was uniformly distributed in the cytoplasm of uninfected cells but was found concentrated in the perinuclear region during late infection where it overlapped with the signal for non-structural protein 2C within the viral replication complex.
- Full Text:
- Date Issued: 2011
- Authors: Mutsvunguma, Lorraine Z , Moetlhoa, Boitumelo , Edkins, Adrienne L , Luke, Garry A , Blatch, Gregory L , Knox, Caroline M
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/165085 , vital:41207 , DOI: 10.1007/s12192-011-0262-x
- Description: Theiler’s murine encephalomyelitis virus (TMEV) is a positive-sense RNA virus belonging to the Cardiovirus genus in the family Picornaviridae. In addition to other host cellular factors and pathways, picornaviruses utilise heat shock proteins (Hsps) to facilitate their propagation in cells. This study investigated the localisation of Hsps 70 and 90 in TMEV-infected BHK-21 cells by indirect immunofluorescence and confocal microscopy. The effect of Hsp90 inhibitors novobiocin (Nov) and geldanamycin (GA) on the development of cytopathic effect (CPE) induced by infection was also examined. Hsp90 staining was uniformly distributed in the cytoplasm of uninfected cells but was found concentrated in the perinuclear region during late infection where it overlapped with the signal for non-structural protein 2C within the viral replication complex.
- Full Text:
- Date Issued: 2011
Localisation of Theiler's murine encephalomyelitis virus protein 2C to the golgi apparatus using antibodies generated against a peptide region:
- Jauka, Tembisa, Mutsvunguma, Lorraine Z, Boshoff, Aileen, Edkins, Adrienne L, Knox, Caroline M
- Authors: Jauka, Tembisa , Mutsvunguma, Lorraine Z , Boshoff, Aileen , Edkins, Adrienne L , Knox, Caroline M
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/165074 , vital:41206 , DOI: 10.1016/j.jviromet.2010.05.009
- Description: The picornavirus 2C protein is highly conserved and indispensible for virus replication. Polyclonal antibodies against Theiler's murine encephalomyelitis virus (TMEV) 2C protein were generated by immunisation of rabbits with a peptide comprising amino acids 31–210 of the protein. Antibodies were used to investigate the localisation of 2C in infected cells by indirect immunofluorescence and confocal microscopy. Analysis of infected cells revealed that the distribution of 2C changed during infection.
- Full Text:
- Date Issued: 2010
- Authors: Jauka, Tembisa , Mutsvunguma, Lorraine Z , Boshoff, Aileen , Edkins, Adrienne L , Knox, Caroline M
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/165074 , vital:41206 , DOI: 10.1016/j.jviromet.2010.05.009
- Description: The picornavirus 2C protein is highly conserved and indispensible for virus replication. Polyclonal antibodies against Theiler's murine encephalomyelitis virus (TMEV) 2C protein were generated by immunisation of rabbits with a peptide comprising amino acids 31–210 of the protein. Antibodies were used to investigate the localisation of 2C in infected cells by indirect immunofluorescence and confocal microscopy. Analysis of infected cells revealed that the distribution of 2C changed during infection.
- Full Text:
- Date Issued: 2010
Cancer stem cells in breast cancer and metastasis:
- Lawson, Jessica C, Blatch, Gregory L, Edkins, Adrienne L
- Authors: Lawson, Jessica C , Blatch, Gregory L , Edkins, Adrienne L
- Date: 2009
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/165057 , vital:41205 , DOI: 10.1007/s10549-009-0524-9
- Description: The cancer stem cell theory poses that cancers develop from a subset of malignant cells that possess stem cell characteristics and has been proposed to account for the development of a variety of malignancies, including breast cancer. These cancer stem cells (CSC) possess characteristics of both stem cells and cancer cells, in that they have the properties of self-renewal, asymmetric cell division, resistance to apoptosis, independent growth, tumourigenicity and metastatic potential. A CSC origin for breast cancer can neatly explain both the heterogeneity of breast cancers and the relapse of the tumours after treatment. However, many reports on CSC in the breast are contradictory. There is variation with respect to how breast cancer stem cells should be identified, their characteristics and a possible lack of correlation between clinical outcome and breast cancer stem cell status of a tumour. These combined factors have made breast cancer stem cells a highly contentious issue. In this review, we highlight the progress in the analysis of cancer stem cells, with an emphasis on breast cancer.
- Full Text:
- Date Issued: 2009
- Authors: Lawson, Jessica C , Blatch, Gregory L , Edkins, Adrienne L
- Date: 2009
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/165057 , vital:41205 , DOI: 10.1007/s10549-009-0524-9
- Description: The cancer stem cell theory poses that cancers develop from a subset of malignant cells that possess stem cell characteristics and has been proposed to account for the development of a variety of malignancies, including breast cancer. These cancer stem cells (CSC) possess characteristics of both stem cells and cancer cells, in that they have the properties of self-renewal, asymmetric cell division, resistance to apoptosis, independent growth, tumourigenicity and metastatic potential. A CSC origin for breast cancer can neatly explain both the heterogeneity of breast cancers and the relapse of the tumours after treatment. However, many reports on CSC in the breast are contradictory. There is variation with respect to how breast cancer stem cells should be identified, their characteristics and a possible lack of correlation between clinical outcome and breast cancer stem cell status of a tumour. These combined factors have made breast cancer stem cells a highly contentious issue. In this review, we highlight the progress in the analysis of cancer stem cells, with an emphasis on breast cancer.
- Full Text:
- Date Issued: 2009
SDF-1 and PDGF enhance αvβ5-mediated ERK activation and adhesion-independent growth of human pre-B cell lines:
- Acharya, Mridu, Edkins, Adrienne L, Ozanne, B, Cushley, W
- Authors: Acharya, Mridu , Edkins, Adrienne L , Ozanne, B , Cushley, W
- Date: 2009
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/165044 , vital:41204 , DOI: 10.1038/leu.2009.126
- Description: CD23 acts through the αvβ5 integrin to promote growth of human pre-B cell lines in an adhesion-independent manner. αvβ5 is expressed on normal B-cell precursors in the bone marrow. Soluble CD23 (sCD23), short CD23-derived peptides containing the arg-lys-cys (RKC) motif recognized by αvβ5 and anti-αvβ5 monoclonal antibodies (MAbs) all sustain growth of pre-B cell lines. The chemokine stromal cell-derived factor-1 (SDF-1) regulates key processes during B-cell development. SDF-1 enhanced the growth-sustaining effect driven by ligation of αvβ5 with anti-αvβ5 MAb 15F-11, sCD23 or CD23-derived RKC-containing peptides. This effect was restricted to B-cell precursors and was specific to SDF-1.
- Full Text:
- Date Issued: 2009
- Authors: Acharya, Mridu , Edkins, Adrienne L , Ozanne, B , Cushley, W
- Date: 2009
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/165044 , vital:41204 , DOI: 10.1038/leu.2009.126
- Description: CD23 acts through the αvβ5 integrin to promote growth of human pre-B cell lines in an adhesion-independent manner. αvβ5 is expressed on normal B-cell precursors in the bone marrow. Soluble CD23 (sCD23), short CD23-derived peptides containing the arg-lys-cys (RKC) motif recognized by αvβ5 and anti-αvβ5 monoclonal antibodies (MAbs) all sustain growth of pre-B cell lines. The chemokine stromal cell-derived factor-1 (SDF-1) regulates key processes during B-cell development. SDF-1 enhanced the growth-sustaining effect driven by ligation of αvβ5 with anti-αvβ5 MAb 15F-11, sCD23 or CD23-derived RKC-containing peptides. This effect was restricted to B-cell precursors and was specific to SDF-1.
- Full Text:
- Date Issued: 2009
A Trypanosoma cruzi heat shock protein 40 is able to stimulate the adenosine triphosphate hydrolysis activity of heat shock protein 70 and can substitute for a yeast heat shock protein 40
- Edkins, Adrienne L, Ludewig, M H, Blatch, Gregory L
- Authors: Edkins, Adrienne L , Ludewig, M H , Blatch, Gregory L
- Date: 2004
- Language: English
- Type: Article
- Identifier: vital:6465 , http://hdl.handle.net/10962/d1005794 , http://dx.doi.org/10.1016/j.biocel.2004.01.016
- Description: The process of assisted protein folding, characteristic of members of the heat shock protein 70 (Hsp70) and heat shock protein 40 (Hsp40) molecular chaperone families, is important for maintaining the structural integrity of cellular protein machinery under normal and stressful conditions. Hsp70 and Hsp40 cooperate to bind non-native protein conformations in a process of adenosine triphosphate (ATP)-regulated assisted protein folding. We have analysed the molecular chaperone activity of the cytoplasmic inducible Hsp70 from Trypanosoma cruzi (TcHsp70) and its interactions with its potential partner Hsp40s (T. cruzi DnaJ protein 1 [Tcj1] and T. cruzi DnaJ protein 2 [Tcj2]). Histidine-tagged TcHsp70 (His-TcHsp70), Tcj1 (Tcj1-His) and Tcj2 (His-Tcj2) were over-produced in Escherichia coli and purified by nickel affinity chromatography. The in vitro basal specific ATP hydrolysis activity (ATPase activity) of His-TcHsp70 was determined as 40 nmol phosphate/min/mg protein, significantly higher than that reported for other Hsp70s. The basal specific ATPase activity was stimulated to a maximal level of 60 nmol phosphate/min/mg protein in the presence of His-Tcj2 and a model substrate, reduced carboxymethylated α-lactalbumin. In vivo complementation assays showed that Tcj2 was able to overcome the temperature sensitivity of the ydj1 mutant Saccharomyces cerevisiae strain JJ160, suggesting that Tcj2 may be functionally equivalent to the yeast Hsp40 homologue (yeast DnaJ protein 1, Ydj1). These data suggest that Tcj2 is involved in cytoprotection in a similar fashion to Ydj1, and that TcHsp70 and Tcj2 may interact in a nucleotide-regulated process of chaperone-assisted protein folding.
- Full Text:
- Date Issued: 2004
- Authors: Edkins, Adrienne L , Ludewig, M H , Blatch, Gregory L
- Date: 2004
- Language: English
- Type: Article
- Identifier: vital:6465 , http://hdl.handle.net/10962/d1005794 , http://dx.doi.org/10.1016/j.biocel.2004.01.016
- Description: The process of assisted protein folding, characteristic of members of the heat shock protein 70 (Hsp70) and heat shock protein 40 (Hsp40) molecular chaperone families, is important for maintaining the structural integrity of cellular protein machinery under normal and stressful conditions. Hsp70 and Hsp40 cooperate to bind non-native protein conformations in a process of adenosine triphosphate (ATP)-regulated assisted protein folding. We have analysed the molecular chaperone activity of the cytoplasmic inducible Hsp70 from Trypanosoma cruzi (TcHsp70) and its interactions with its potential partner Hsp40s (T. cruzi DnaJ protein 1 [Tcj1] and T. cruzi DnaJ protein 2 [Tcj2]). Histidine-tagged TcHsp70 (His-TcHsp70), Tcj1 (Tcj1-His) and Tcj2 (His-Tcj2) were over-produced in Escherichia coli and purified by nickel affinity chromatography. The in vitro basal specific ATP hydrolysis activity (ATPase activity) of His-TcHsp70 was determined as 40 nmol phosphate/min/mg protein, significantly higher than that reported for other Hsp70s. The basal specific ATPase activity was stimulated to a maximal level of 60 nmol phosphate/min/mg protein in the presence of His-Tcj2 and a model substrate, reduced carboxymethylated α-lactalbumin. In vivo complementation assays showed that Tcj2 was able to overcome the temperature sensitivity of the ydj1 mutant Saccharomyces cerevisiae strain JJ160, suggesting that Tcj2 may be functionally equivalent to the yeast Hsp40 homologue (yeast DnaJ protein 1, Ydj1). These data suggest that Tcj2 is involved in cytoprotection in a similar fashion to Ydj1, and that TcHsp70 and Tcj2 may interact in a nucleotide-regulated process of chaperone-assisted protein folding.
- Full Text:
- Date Issued: 2004
Expanding the SAR of Nontoxic Antiplasmodial Indolyl-3-ethanone Ethers and Thioethers.
- Lunga, Mayibongwe J, Chisango, Ruramai Lissa, Weyers, Carli, Isaacs, Michelle, Taylor, Dale, Edkins, Adrienne L, Khanye, Setshaba D, Hoppe, Heinrich C, Veale, Clinton G L
- Authors: Lunga, Mayibongwe J , Chisango, Ruramai Lissa , Weyers, Carli , Isaacs, Michelle , Taylor, Dale , Edkins, Adrienne L , Khanye, Setshaba D , Hoppe, Heinrich C , Veale, Clinton G L
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/122908 , vital:35370 , https://doi.org/10.1002/cmdc.201800235
- Description: Despite major strides in reducing Plasmodium falciparum infections, this parasite still accounts for roughly half a million annual deaths. This problem is compounded by the decreased efficacy of artemisinin combination therapies. Therefore, the development and optimisation of novel antimalarial chemotypes is critical. In this study, we describe our strategic approach to optimise a class of previously reported antimalarials, resulting in the discovery of 1‐(5‐chloro‐1H‐indol‐3‐yl)‐2‐[(4‐cyanophenyl)thio]ethanone (13) and 1‐(5‐chloro‐1H‐indol‐3‐yl)‐2‐[(4‐nitrophenyl)thio]ethanone (14), whose activity was equipotent to that of chloroquine against the P. falciparum 3D7 strain. Furthermore, these compounds were found to be nontoxic to HeLa cells as well as being non‐haemolytic to uninfected red blood cells. Intriguingly, several of our most promising compounds were found to be less active against the isogenic NF54 strain, highlighting possible issues with long‐term dependability of malarial strains. Finally compound 14 displayed similar activity against both the NF54 and K1 strains, suggesting that it inhibits a pathway that is uncompromised by K1 resistance.
- Full Text:
- Authors: Lunga, Mayibongwe J , Chisango, Ruramai Lissa , Weyers, Carli , Isaacs, Michelle , Taylor, Dale , Edkins, Adrienne L , Khanye, Setshaba D , Hoppe, Heinrich C , Veale, Clinton G L
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/122908 , vital:35370 , https://doi.org/10.1002/cmdc.201800235
- Description: Despite major strides in reducing Plasmodium falciparum infections, this parasite still accounts for roughly half a million annual deaths. This problem is compounded by the decreased efficacy of artemisinin combination therapies. Therefore, the development and optimisation of novel antimalarial chemotypes is critical. In this study, we describe our strategic approach to optimise a class of previously reported antimalarials, resulting in the discovery of 1‐(5‐chloro‐1H‐indol‐3‐yl)‐2‐[(4‐cyanophenyl)thio]ethanone (13) and 1‐(5‐chloro‐1H‐indol‐3‐yl)‐2‐[(4‐nitrophenyl)thio]ethanone (14), whose activity was equipotent to that of chloroquine against the P. falciparum 3D7 strain. Furthermore, these compounds were found to be nontoxic to HeLa cells as well as being non‐haemolytic to uninfected red blood cells. Intriguingly, several of our most promising compounds were found to be less active against the isogenic NF54 strain, highlighting possible issues with long‐term dependability of malarial strains. Finally compound 14 displayed similar activity against both the NF54 and K1 strains, suggesting that it inhibits a pathway that is uncompromised by K1 resistance.
- Full Text:
Novobiocin–ferrocene conjugates possessing anticancer and antiplasmodial activity independent of HSP90 inhibition.
- Mbaba, Mziyanda, de la Mare, Jo-Anne, Sterrenberg, Jason N, Kajewole, Deborah, Maharaj, Shantal, Edkins, Adrienne L, Isaacs, Michelle, Hoppe, Heinrich C, Khanye, Setshaba D
- Authors: Mbaba, Mziyanda , de la Mare, Jo-Anne , Sterrenberg, Jason N , Kajewole, Deborah , Maharaj, Shantal , Edkins, Adrienne L , Isaacs, Michelle , Hoppe, Heinrich C , Khanye, Setshaba D
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/122858 , vital:35359 , https://doi.org/10.1007/s00775-018-1634-9
- Description: A series of tailored novobiocin–ferrocene conjugates was prepared in moderate yields and investigated for in vitro anticancer and antiplasmodial activity against the MDA-MB-231 breast cancer line and Plasmodium falciparum 3D7 strain, respectively. While the target compounds displayed moderate anticancer activity against the breast cancer cell line with IC50 values in the mid-micromolar range, compounds 10a–c displayed promising antiplasmodial activity as low as 0.889 µM. Furthermore, the most promising compounds were tested for inhibitory effects against a postulated target, heat shock protein 90 (Hsp90).
- Full Text:
- Authors: Mbaba, Mziyanda , de la Mare, Jo-Anne , Sterrenberg, Jason N , Kajewole, Deborah , Maharaj, Shantal , Edkins, Adrienne L , Isaacs, Michelle , Hoppe, Heinrich C , Khanye, Setshaba D
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/122858 , vital:35359 , https://doi.org/10.1007/s00775-018-1634-9
- Description: A series of tailored novobiocin–ferrocene conjugates was prepared in moderate yields and investigated for in vitro anticancer and antiplasmodial activity against the MDA-MB-231 breast cancer line and Plasmodium falciparum 3D7 strain, respectively. While the target compounds displayed moderate anticancer activity against the breast cancer cell line with IC50 values in the mid-micromolar range, compounds 10a–c displayed promising antiplasmodial activity as low as 0.889 µM. Furthermore, the most promising compounds were tested for inhibitory effects against a postulated target, heat shock protein 90 (Hsp90).
- Full Text: