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Enhancing The Conformational Stability Of The Cl-Par-4 Tumor Suppressor Via Site-Directed Mutagenesis, Samjhana Pandey, Krishna K. Raut, Andrea M. Clark, Antoine Baudin, Lamya Djemri, David S. Libich, Komala Ponniah, Steven M. Pascal
Enhancing The Conformational Stability Of The Cl-Par-4 Tumor Suppressor Via Site-Directed Mutagenesis, Samjhana Pandey, Krishna K. Raut, Andrea M. Clark, Antoine Baudin, Lamya Djemri, David S. Libich, Komala Ponniah, Steven M. Pascal
Chemistry & Biochemistry Faculty Publications
Intrinsically disordered proteins play important roles in cell signaling, and dysregulation of these proteins is associated with several diseases. Prostate apoptosis response-4 (Par-4), an approximately 40 kilodalton proapoptotic tumor suppressor, is a predominantly intrinsically disordered protein whose downregulation has been observed in various cancers. The caspase-cleaved fragment of Par-4 (cl-Par-4) is active and plays a role in tumor suppression by inhibiting cell survival pathways. Here, we employed site-directed mutagenesis to create a cl-Par-4 point mutant (D313K). The expressed and purified D313K protein was characterized using biophysical techniques, and the results were compared to that of the wild-type (WT). We have …
Tumor Suppressor Par-4 Regulates Complement Factor C3 And Obesity, Nathália Araujo, James Sledziona, Sunil K. Noothi, Ravshan Burikhanov, Nikhil Hebbar, Saptadwipa Ganguly, Tripti Shrestha-Bhattarai, Beibei Zhu, Wendy S. Katz, Yi Zhang, Barry S. Taylor, Jinze Liu, Li Chen, Heidi L. Weiss, Daheng He, Chi Wang, Andrew J. Morris, Lisa A. Cassis, Mariana N. Nikolova‑Karakashian, Prabhakara R. Nagareddy, Olle Melander, B. Mark Evers, Phillip A. Kern, Vivek M. Rangnekar
Tumor Suppressor Par-4 Regulates Complement Factor C3 And Obesity, Nathália Araujo, James Sledziona, Sunil K. Noothi, Ravshan Burikhanov, Nikhil Hebbar, Saptadwipa Ganguly, Tripti Shrestha-Bhattarai, Beibei Zhu, Wendy S. Katz, Yi Zhang, Barry S. Taylor, Jinze Liu, Li Chen, Heidi L. Weiss, Daheng He, Chi Wang, Andrew J. Morris, Lisa A. Cassis, Mariana N. Nikolova‑Karakashian, Prabhakara R. Nagareddy, Olle Melander, B. Mark Evers, Phillip A. Kern, Vivek M. Rangnekar
Clinical and Translational Science Faculty Publications
Prostate apoptosis response-4 (Par-4) is a tumor suppressor that induces apoptosis in cancer cells. However, the physiological function of Par-4 remains unknown. Here we show that conventional Par-4 knockout (Par-4-/-) mice and adipocyte-specific Par-4 knockout (AKO) mice, but not hepatocyte-specific Par-4 knockout mice, are obese with standard chow diet. Par-4-/- and AKO mice exhibit increased absorption and storage of fat in adipocytes. Mechanistically, Par-4 loss is associated with mdm2 downregulation and activation of p53. We identified complement factor c3 as a p53-regulated gene linked to fat storage in adipocytes. Par-4 re-expression in adipocytes or c3 deletion reversed …
Methylation Of The D2 Dopamine Receptor Affects Binding With The Human Regulatory Proteins Par-4 And Calmodulin, Alexander Bowitch, Ansuman Sahoo, Andrea M. Clark, Christiana Ntangka, Krishna K. Raut, Paul Gollnick, Michael C. Yu, Steven M. Pascal, Sarah E. Walker, Denise M. Ferkey
Methylation Of The D2 Dopamine Receptor Affects Binding With The Human Regulatory Proteins Par-4 And Calmodulin, Alexander Bowitch, Ansuman Sahoo, Andrea M. Clark, Christiana Ntangka, Krishna K. Raut, Paul Gollnick, Michael C. Yu, Steven M. Pascal, Sarah E. Walker, Denise M. Ferkey
Chemistry & Biochemistry Faculty Publications
No abstract provided.
Structual Analysis Of The Cl-Par-4 Tumor Suppressor As A Function Of Ionic Environment, Krishna K. Raut, Komala Ponniah, Steven M. Pascal
Structual Analysis Of The Cl-Par-4 Tumor Suppressor As A Function Of Ionic Environment, Krishna K. Raut, Komala Ponniah, Steven M. Pascal
Chemistry & Biochemistry Faculty Publications
Prostate apoptosis response-4 (Par-4) is a proapoptotic tumor suppressor protein that has been linked to a large number of cancers. This 38 kilodalton (kDa) protein has been shown to be predominantly intrinsically disordered in vitro. In vivo, Par-4 is cleaved by caspase-3 at Asp-131 to generate the 25 kDa functionally active cleaved Par-4 protein (cl-Par-4) that inhibits NF-κB-mediated cell survival pathways and causes selective apoptosis in tumor cells. Here, we have employed circular dichroism (CD) spectroscopy and dynamic light scattering (DLS) to assess the effects of various monovalent and divalent salts upon the conformation of cl-Par-4 in vitro. We have …
Chloroquine Induction Par-4 And Treatment Of Cancer, Vivek M. Rangnekar
Chloroquine Induction Par-4 And Treatment Of Cancer, Vivek M. Rangnekar
Radiation Medicine Faculty Patents
Described herein are methods for treating cancer in a subject in need thereof by administering chloroquine, or a salt or prodrug thereof, optionally with another agent that promotes Par-4 production to induce prostate apoptosis response-4 (Par-4) production by host cells, particularly non-cancerous host cells, to promote apoptosis in cancer cells, including androgen insensitive prostate cancer cells.
A Naturally Generated Decoy Of The Prostate Apoptosis Response-4 Protein Overcomes Therapy Resistance In Tumors, Nikhil Hebbar, Ravshan Burikhanov, Nidhi Shukla, Shirley Qiu, Yanming Zhao, Kojo S. J. Elenitoba-Johnson, Vivek M. Rangnekar
A Naturally Generated Decoy Of The Prostate Apoptosis Response-4 Protein Overcomes Therapy Resistance In Tumors, Nikhil Hebbar, Ravshan Burikhanov, Nidhi Shukla, Shirley Qiu, Yanming Zhao, Kojo S. J. Elenitoba-Johnson, Vivek M. Rangnekar
Radiation Medicine Faculty Publications
Primary tumors are often heterogeneous, composed of therapy-sensitive and emerging therapy-resistant cancer cells. Interestingly, treatment of therapy-sensitive tumors in heterogeneous tumor microenvironments results in apoptosis of therapy-resistant tumors. In this study, we identify a prostate apoptosis response-4 (Par-4) amino-terminal fragment (PAF) that is released by diverse therapy-sensitive cancer cells following therapy-induced caspase cleavage of the tumor suppressor Par-4 protein. PAF caused apoptosis in cancer cells resistant to therapy and inhibited tumor growth. A VASA segment of Par-4 mediated its binding and degradation by the ubiquitin ligase Fbxo45, resulting in loss of Par-4 proapoptotic function. Conversely, PAF, which contains this VASA …
Chloroquine-Inducible Par-4 Secretion Is Essential For Tumor Cell Apoptosis And Inhibition Of Metastasis, Ravshan Burikhanov, Nikhil Hebbar, Sunil K. Noothi, Nidhi Shukla, James Sledziona, Nathália Araujo, Meghana Kudrimoti, Qing Jun Wang, David S. Watt, Danny R. Welch, Jodi Maranchie, Akihiro Harada, Vivek M. Rangnekar
Chloroquine-Inducible Par-4 Secretion Is Essential For Tumor Cell Apoptosis And Inhibition Of Metastasis, Ravshan Burikhanov, Nikhil Hebbar, Sunil K. Noothi, Nidhi Shukla, James Sledziona, Nathália Araujo, Meghana Kudrimoti, Qing Jun Wang, David S. Watt, Danny R. Welch, Jodi Maranchie, Akihiro Harada, Vivek M. Rangnekar
Radiation Medicine Faculty Publications
The induction of tumor suppressor proteins capable of cancer cell apoptosis represents an attractive option for the re-purposing of existing drugs. We report that the anti-malarial drug, chloroquine (CQ), is a robust inducer of Par-4 secretion from normal cells in mice and cancer patients in a clinical trial. CQ-inducible Par-4 secretion triggers paracrine apoptosis of cancer cells and also inhibits metastatic tumor growth. CQ induces Par-4 secretion via the classical secretory pathway that requires the activation of p53. Mechanistically, p53 directly induces Rab8b, a GTPase essential for vesicle transport of Par-4 to the plasma membrane prior to secretion. Our findings …
Regulation Of The Proapoptotic Functions Of Prostate Apoptosis Response-4 (Par-4) By Casein Kinase 2 In Prostate Cancer Cells, A De Thonel, A Hazoumé, V Kochin, K Isoniemi, G Jego, E Fourmaux, A Hammann, H Mjahed, O Filhol, O Micheau, P Rocchi, V Mezger, J E Eriksson, Vivek M. Rangnekar, C Garrido
Regulation Of The Proapoptotic Functions Of Prostate Apoptosis Response-4 (Par-4) By Casein Kinase 2 In Prostate Cancer Cells, A De Thonel, A Hazoumé, V Kochin, K Isoniemi, G Jego, E Fourmaux, A Hammann, H Mjahed, O Filhol, O Micheau, P Rocchi, V Mezger, J E Eriksson, Vivek M. Rangnekar, C Garrido
Radiation Medicine Faculty Publications
The proapoptotic protein, prostate apoptosis response-4 (Par-4), acts as a tumor suppressor in prostate cancer cells. The serine/threonine kinase casein kinase 2 (CK2) has a well-reported role in prostate cancer resistance to apoptotic agents or anticancer drugs. However, the mechanistic understanding on how CK2 supports survival is far from complete. In this work, we demonstrate both in rat and humans that (i) Par-4 is a new substrate of the survival kinase CK2 and (ii) phosphorylation by CK2 impairs Par-4 proapoptotic functions. We also unravel different levels of CK2-dependent regulation of Par-4 between species. In rats, the phosphorylation by CK2 at …
Paracrine Apoptotic Effect Of P53 Mediated By Tumor Suppressor Par-4, Ravshan Burikhanov, Tripti Shrestha-Bhattarai, Nikhil Hebbar, Shirley Qiu, Yanming Zhao, Gerard P. Zambetti, Vivek M. Rangnekar
Paracrine Apoptotic Effect Of P53 Mediated By Tumor Suppressor Par-4, Ravshan Burikhanov, Tripti Shrestha-Bhattarai, Nikhil Hebbar, Shirley Qiu, Yanming Zhao, Gerard P. Zambetti, Vivek M. Rangnekar
Radiation Medicine Faculty Publications
The guardian of the genome, p53, is often mutated in cancer and may contribute to therapeutic resistance. Given that p53 is intact and functional in normal tissues, we harnessed its potential to inhibit the growth of p53-deficient cancer cells. Specific activation of p53 in normal fibroblasts selectively induced apoptosis in p53-deficient cancer cells. This paracrine effect was mediated by p53-dependent secretion of the tumor suppressor Par-4. Accordingly, the activation of p53 in normal mice, but not p53−/− or Par-4−/− mice, caused systemic elevation of Par-4, which induced apoptosis of p53-deficient tumor cells. Mechanistically, p53 …
Identification Of A Unique Core Domain Of Par-4 Sufficient For Selective Apoptosis Induction In Cancer Cells, Vivek M. Rangnekar
Identification Of A Unique Core Domain Of Par-4 Sufficient For Selective Apoptosis Induction In Cancer Cells, Vivek M. Rangnekar
Radiation Medicine Faculty Patents
The present invention relates to Par-4 mutants which cause apoptosis in cancer cells which are sensitive to Par-4 and also induce apoptosis in cancer cells which are resistant to Par-4. The present invention also relates to methods of using the Par-4 mutant to treat certain cancers, as well as to kits, vectors, and polypeptides for same.