Browsing by Subject "Tumor suppressor proteins"
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Item Deleted in malignant brain tumor 1 genetic variation confers urinary tract infection risk in children and mice(Wiley, 2021-07) Hains, David S.; Polley, Shamik; Liang, Dong; Saxena, Vijay; Arregui, Samuel; Ketz, John; Barr-Beare, Evan; Rawson, Ashley; Spencer, John D.; Cohen, Ariel; Hansen, Pernille L.; Tuttolomondo, Martina; Casella, Cinzia; Ditzel, Henrik J.; Cohen, Daniel; Hollox, Edward J.; Schwaderer, Andrew L.; Pediatrics, School of MedicineItem Enhancement of the SESN2-SHP cascade by melatonin ameliorates hepatic gluconeogenesis by inhibiting the CRBN-BTG2-CREBH signaling pathway(Springer Nature, 2023) An, Seungwon; Nedumaran, Balachandar; Koh, Hong; Joo, Dong Jin; Lee, Hyungjo; Park, Chul-Seung; Harris, Robert A.; Shin, Keong Sub; Djalilian, Ali R.; Kim, Yong Deuk; Biochemistry and Molecular Biology, School of MedicineMelatonin is involved in the regulation of various biological functions. Here, we explored a novel molecular mechanism by which the melatonin-induced sestrin2 (SESN2)-small heterodimer partner (SHP) signaling pathway protects against fasting- and diabetes-mediated hepatic glucose metabolism. Various key gene expression analyses were performed and multiple metabolic changes were assessed in liver specimens and primary hepatocytes of mice and human participants. The expression of the hepatic cereblon (CRBN) and b-cell translocation gene 2 (BTG2) genes was significantly increased in fasting mice, diabetic mice, and patients with diabetes. Overexpression of Crbn and Btg2 increased hepatic gluconeogenesis by enhancing cyclic adenosine monophosphate (cAMP)-responsive element-binding protein H (CREBH), whereas this phenomenon was prominently ablated in Crbn null mice and Btg2-silenced mice. Interestingly, melatonin-induced SESN2 and SHP markedly reduced hepatic glucose metabolism in diabetic mice and primary hepatocytes, and this protective effect of melatonin was strikingly reversed by silencing Sesn2 and Shp. Finally, the melatonin-induced SESN2-SHP signaling pathway inhibited CRBN- and BTG2-mediated hepatic gluconeogenic gene transcription via the competition of BTG2 and the interaction of CREBH. Mitigation of the CRBN-BTG2-CREBH axis by the melatonin-SESN2-SHP signaling network may provide a novel therapeutic strategy to treat metabolic dysfunction due to diabetes.Item Expression of Human Papillomavirus Type 16 E7 Is Sufficient To Significantly Increase Expression of Angiogenic Factors But Is Not Sufficient To Induce Endothelial Cell Migration(2010-10-21) Walker, Joanna Antigone; Roman, Ann; Cornetta, Kenneth; Clapp, Wade D.; Goebl, Mark, 1958-Human papillomavirus 16 (HPV 16) causes cancer. Two viral oncoproteins of HPV 16, E6 and E7, are consistently expressed in these cancers. HPV 16 E6 and E7 proteins target p53 and Rb family members, respectively, for degradation thus inactivating the functiond of these tumor suppressor proteins. Tumor development requires the acquisition of a blood supply, a process known as angiogenesis. Tumor suppressors negatively regulate angigogenesis. Expression of HPV 16 E6 and E7 together in human foreskin keratinocytes (HFKs) increases the level of angiogenic inducers vascular endothelial growth factor (VEGF) and interleukin-8 (IL-8). Further, conditioned media from such cells are sufficient to alter endothelial cell behavior both in vitro and in vivo. To determine the individual contributions of HPV E6 and E7 to angiogenesis, translational termination linkers (TTLs) were inserted into the coding region of E6 or E7. Following retroviral transduction of the mutated cassette into HFKs, the ability of E7 in the context of the E6TTL mutation (E6TTLE7) and E6 in the context of the E7TTL mutation (E6E7TTL) to induce VEGF and IL-8 was compared to the LXSN control retrovirus. E7 and, to a lesser extent E6, increased the expression of VEGF and IL-8. Migration of human microvascular endothelial cells was not induced using conditioned media from either E6 or E7 expressing cells. Since the increased levels of VEGF and IL-8 induced by HPV 16E6ETTLE7 were not sufficient to alter endothelial cell behavior, immunological depletion experiments were used to determine whether either angiogenic factor was required for HPV 16E6 and E7 together to induce HMVEC migration. Only VEGF was required. Preliminary data suggest that the ability of HPV 16 E7 to induce angiogenic factors is dependent upon degradation of a specific Rb family member.Item Genome sequencing analysis identifies new loci associated with Lewy body dementia and provides insights into its genetic architecture(Springer Nature, 2021-03) Chia, Ruth; Sabir, Marya S.; Bandres-Ciga, Sara; Saez-Atienzar, Sara; Reynolds, Regina H.; Gustavsson, Emil; Walton, Ronald L.; Ahmed, Sarah; Viollet, Coralie; Ding, Jinhui; Makarious, Mary B.; Diez-Fairen, Monica; Portley, Makayla K.; Shah, Zalak; Abramzon, Yevgeniya; Hernandez, Dena G.; Blauwendraat, Cornelis; Stone, David J.; Eicher, John; Parkkinen, Laura; Ansorge, Olaf; Clark, Lorraine; Honig, Lawrence S.; Marder, Karen; Lemstra, Afina; St. George-Hyslop, Peter; Londos, Elisabet; Morgan, Kevin; Lashley, Tammaryn; Warner, Thomas T.; Jaunmuktane, Zane; Galasko, Douglas; Santana, Isabel; Tienari, Pentti J.; Myllykangas, Liisa; Oinas, Minna; Cairns, Nigel J.; Morris, John C.; Halliday, Glenda M.; Van Deerlin, Vivianna M.; Trojanowski, John Q.; Grassano, Maurizio; Calvo, Andrea; Mora, Gabriele; Canosa, Antonio; Floris, Gianluca; Bohannan, Ryan C.; Brett, Francesca; Gan-Or, Ziv; Geiger, Joshua T.; Moore, Anni; May, Patrick; Krüger, Rejko; Goldstein, David S.; Lopez, Grisel; Tayebi, Nahid; Sidransky, Ellen; Norcliffe-Kaufmann, Lucy; Palma, Jose-Alberto; Kaufmann, Horacio; Shakkottai, Vikram G.; Perkins, Matthew; Newell, Kathy L.; Gasser, Thomas; Schulte, Claudia; Landi, Francesco; Salvi, Erika; Cusi, Daniele; Masliah, Eliezer; Kim, Ronald C.; Caraway, Chad A.; Monuki, Edwin S.; Brunetti, Maura; Dawson, Ted M.; Rosenthal, Liana S.; Albert, Marilyn S.; Pletnikova, Olga; Troncoso, Juan C.; Flanagan, Margaret E.; Mao, Qinwen; Bigio, Eileen H.; Rodríguez-Rodríguez, Eloy; Infante, Jon; Lage, Carmen; González-Aramburu, Isabel; Sanchez-Juan, Pascual; Ghetti, Bernardino; Keith, Julia; Black, Sandra E.; Masellis, Mario; Rogaeva, Ekaterina; Duyckaerts, Charles; Brice, Alexis; Lesage, Suzanne; Xiromerisiou, Georgia; Barrett, Matthew J.; Tilley, Bension S.; Gentleman, Steve; Logroscino, Giancarlo; Serrano, Geidy E.; Beach, Thomas G.; McKeith, Ian G.; Thomas, Alan J.; Attems, Johannes; Morris, Christopher M.; Palmer, Laura; Love, Seth; Troakes, Claire; Al-Sarraj, Safa; Hodges, Angela K.; Aarsland, Dag; Klein, Gregory; Kaiser, Scott M.; Woltjer, Randy; Pastor, Pau; Bekris, Lynn M.; Leverenz, James B.; Besser, Lilah M.; Kuzma, Amanda; Renton, Alan E.; Goate, Alison; Bennett, David A.; Scherzer, Clemens R.; Morris, Huw R.; Ferrari, Raffaele; Albani, Diego; Pickering-Brown, Stuart; Faber, Kelley; Kukull, Walter A.; Morenas-Rodriguez, Estrella; Lleó, Alberto; Fortea, Juan; Alcolea, Daniel; Clarimon, Jordi; Nalls, Mike A.; Ferrucci, Luigi; Resnick, Susan M.; Tanaka, Toshiko; Foroud, Tatiana M.; Graff-Radford, Neill R.; Wszolek, Zbigniew K.; Ferman, Tanis; Boeve, Bradley F.; Hardy, John A.; Topol, Eric J.; Torkamani, Ali; Singleton, Andrew B.; Ryten, Mina; Dickson, Dennis W.; Chiò, Adriano; Ross, Owen A.; Gibbs, J. Raphael; Dalgard, Clifton L.; Traynor, Bryan J.; Scholz, Sonja W.; Pathology and Laboratory Medicine, School of MedicineThe genetic basis of Lewy body dementia (LBD) is not well understood. Here, we performed whole-genome sequencing in large cohorts of LBD cases and neurologically healthy controls to study the genetic architecture of this understudied form of dementia, and to generate a resource for the scientific community. Genome-wide association analysis identified five independent risk loci, whereas genome-wide gene-aggregation tests implicated mutations in the gene GBA. Genetic risk scores demonstrate that LBD shares risk profiles and pathways with Alzheimer's disease and Parkinson's disease, providing a deeper molecular understanding of the complex genetic architecture of this age-related neurodegenerative condition.Item The oncogenic properties of Amot80 in mammary epithelia(2013-07) Ranahan, William P.; Wells, Clark D.; Herbert, Brittney-Shea; Quilliam, Lawrence; Wek, Ronald C.While breast cancer is the second most commonly diagnosed cancer worldwide, its causes and natural history are not well defined. The female mammary organ is unique in that it does not reach full maturity until the lactation cycle following pregnancy. This cycle entails extensive growth and reorganization of the primitive epithelial ductal network. Following lactation, these same epithelial cells undergo an equally extensive program of apoptosis and involution. The mammary gland's sensitivity to pro-growth and pro-apoptotic signals may partly explain its proclivity to develop cancers. For epithelial cells to become transformed they must lose intracellular organization known as polarity as differentiated epithelial tissues are refractory to aberrant growth. One essential component of epithelial to mesenchymal transition is the intrinsic capacity of cells to repurpose polarity constituents to promote growth. Recently, a novel mechanism of organ size control has been shown to repurpose the apical junctional associated protein Yap into the nucleus where it functions as a transcriptional coactivator promoting growth and dedifferentiation. The focus of my work has been on a family of adaptor proteins termed Amots that have been shown to scaffold Yap and inhibit growth signaling. Specifically, I have shown that the 80KDa form of Amot, termed Amot80, acts as a dominant negative to the other Amot proteins to promote cell growth while reducing cell differentiation. Amot80 was found to promote the prolonged activation of MAPK signaling. Further, Amot80 expression was also found to enhance the transcriptional activity of Yap. This effect likely underlies the ability of Amot80 to drive disorganized overgrowth of MCF10A cells grown in Matrigel̈™. Overall, these data suggest a mechanism whereby the balance of Amot proteins controls the equilibrium between growth and differentiation within mammary epithelial tissues.Item PDZ proteins SCRIB and DLG1 regulate myeloma cell surface CD86 expression, growth, and survival(American Association for Cancer Research, 2022) Moser-Katz, Tyler; Gavile, Catherine M.; Barwick, Benjamin G.; Lee, Kelvin P.; Boise, Lawrence H.; Medicine, School of MedicineDespite advances in the treatment of multiple myeloma in the past decades, the disease remains incurable, and understanding signals and molecules that can control myeloma growth and survival are important for the development of novel therapeutic strategies. One such molecule, CD86, regulates multiple myeloma cell survival via its interaction with CD28 and signaling through its cytoplasmic tail. Although the CD86 cytoplasmic tail has been shown to be involved in drug resistance and can induce molecular changes in multiple myeloma cells, its function has been largely unexplored. Here, we show that CD86 cytoplasmic tail has a role in trafficking CD86 to the cell surface. This is due in part to a PDZ-binding motif at its C-terminus which is important for proper trafficking from the Golgi apparatus. BioID analysis revealed 10 PDZ domain-containing proteins proximal to CD86 cytoplasmic tail in myeloma cells. Among them, we found the planar cell polarity proteins, SCRIB and DLG1, are important for proper CD86 surface expression and the growth and survival of myeloma cells. These findings indicate a mechanism by which myeloma cells confer cellular survival and drug resistance and indicate a possible motif to target for therapeutic gain.Item Phospho-regulation and metastatic potential of Murine Double Minute 2(2012-08) Batuello, Christopher N.; Mayo, Lindsey D.; Dynlacht, Joseph R.; Goebl, Mark G.; Pollok, Karen E.Murine double minute (Mdm2) is a highly modified and multi-faceted protein that is overexpressed in numerous human malignancies. It engages in many cellular activities and is essential for development since deletion of mdm2 is lethal in early stages of embryonic development. The most studied function of Mdm2 is as a negative regulator of the tumor suppressor protein p53. Mdm2 achieves this regulation by binding to p53 and inhibiting p53 transcriptional activity. Mdm2 also functions as an E3 ubiquitin ligase that signals p53 for destruction by the proteasome. Interestingly recent evidence has shown that Mdm2 can also function as an E3 neddylating enzyme that can conjugate the ubiquitin-like molecule, nedd8, to p53. This modification results in inhibition of p53 activity, while maintaining p53 protein levels. While the signaling events that regulate Mdm2 E3 ubiquitin ligase activity have been extensively studied, what activates the neddylating activity of Mdm2 has remained elusive. My investigations have centered on understanding whether tyrosine kinase signaling could activate the neddylating activity of Mdm2. I have shown that c-Src, a non-receptor protein tyrosine kinase that is involved in a variety of cellular processes, phosphorylates Mdm2 on tyrosines 281 and 302. This phosphorylation event increases the half-life and neddylating activity of Mdm2 resulting in a neddylation dependent reduction of p53 transcriptional activity. Mdm2 also has many p53-independent cellular functions that are beginning to be linked to its role as an oncogene. There is an emerging role for Mdm2 in tumor metastasis. Metastasis is a process involving tumor cells migrating from a primary site to a distal site and is a major cause of morbidity and mortality in cancer patients. To date, the involvement of Mdm2 in breast cancer metastasis has only been correlative, with no in vivo model to definitively define a role for Mdm2. Here I have shown in vivo that Mdm2 enhances breast to lung metastasis through the up regulation of multiple angiogenic factors, including HIF-1 alpha and VEGF. Taken together my data provide novel insights into important p53-dependent and independent functions of Mdm2 that represent potential new avenues for therapeutic intervention.Item Proximal Tubule Proliferation Is Insufficient to Induce Rapid Cyst Formation after Cilia Disruption(Wolters Kluwer, 2013) Sharma, Neeraj; Malarky, Erik B.; Berbari, Nicholas F.; O'Connor, Amber K.; Vanden Heuvel, Gregory B.; Mrug, Michal; Yoder, Bradley K.; Biology, School of ScienceDisrupting the function of cilia in mouse kidneys results in rapid or slow progression of cystic disease depending on whether the animals are juveniles or adults, respectively. Renal injury can also markedly accelerate the renal cyst formation that occurs after disruption of cilia in adult mice. Rates of cell proliferation are markedly higher in juvenile than adult kidneys and increase after renal injury, suggesting that cell proliferation may enhance the development of cysts. Here, we induced cilia loss in the kidneys of adult mice in the presence or absence of a Cux-1 transgene, which maintains cell proliferation. By using this model, we were able to avoid additional factors such as inflammation and dedifferentiation, which associate with renal injury and may also influence the rate of cystogenesis. After induction of cilia loss, cystic disease was not more pronounced in adult mice with the Cux-1 transgene compared with those without the transgene. In conclusion, these data suggest that proliferation is unlikely to be the sole mechanism underlying the rapid cystogenesis observed after injury in mice that lose cilia function in adulthood.Item The tumor suppressing roles of tissue structure in cervical cancer development(2012-12) Nguyen, Hoa Bich; Quilliam, Lawrence; Brutkiewicz, Randy R.; Harrington, Maureen A.; Kapur, Reuben; Wells, Clark D.Cervical cancer is caused by the persistent infection of human papilloma virus (HPV) in the cervix epithelium. Although effective preventative care is available, the widespread nature of infection and the variety of HPV strains unprotected by HPV vaccines necessitate a better understanding of the disease for development of new therapies. A major tumor suppressing mechanism is the inhibition of cell division by tissue structure; however, the underlining molecular circuitry for this regulation remains unclear. Recently, the Yap transcriptional co-activator has emerged as a key growth promoter that mediates contact growth arrest and limits organ size. Thus, we aimed to uncover upstream signals that connect tissue organization to Yap regulation in the inhibition of cervical cancer. Two events that disrupt tissue structure were examined including the loss of the tumor suppressor LKB1 and the expression of the viral oncogene HPV16-E6. We identified that Yap mediates cell growth regulation downstream of both LKB1 and E6. Restoration of LKB1 expression in HeLa cervical cancer cells, which lack this tumor suppressor, or shRNA knockdown of LKB1 in NTERT immortalized normal human dermal keratinocytes, demonstrated that LKB1 promotes Yap phosphorylation, nuclear exclusion, and proteasomal degradation. The ability of phosphorylation-defective Yap mutants to rescue LKB1 phenotypes, such as reduced cell proliferation and cell size, suggest that Yap inhibition contributes to LKB1 tumor suppressor function(s). Interestingly, LKB1’s suppression of Yap activity required neither the canonical Yap kinases, Lats1/2, nor metabolic downstream targets of LKB1, AMPK and mTORC1. Instead, the scaffolding protein NF2 was required for LKB1 to induce a specific actin cytoskeleton structure that associates with Yap suppression. Meanwhile, HPV16-E6 promoted Yap activation in all stages of keratinocyte differentiation. E6 activated the Rap1 small GTPase, which in turn promoted Yap activity. Since Rap1 does not mediate differentiation inhibition caused by E6, E6 may play a role in promoting cell growth through Rap1-Yap activation rather than preventing growth arrest through the disruption of differentiation. Altogether, the LKB1-NF2-Yap and E6-Rap1-Yap pathways represent two examples of a novel phenomenon, whereby the structure of a cell directly influences its gene expression and proliferation.Item Validation-based insertional mutagenesis (VBIM) technology identifies adenomatous polypossis coli (APC) like protein (ALP) as a novel negative regulator of NF-κB(2015-01) Mundade, Rasika S.; Lu, Tao; Sullivan, William J., Jr.; Safa, Ahmad R.Colorectal cancer (CRC) is the third leading cause of cancer related deaths in the United States. The nuclear factor κB (NF-κB) is an important family of transcription factors whose aberrant activation has been found in many types of cancer, including CRC. Therefore, understanding the regulation of NF-κB is of ultimate importance for cancer therapy. Using a novel validation-based insertional mutagenesis (VBIM) strategy, our lab has identified the novel adenomatous polyposis coli (APC) like protein (ALP) gene as a negative regulator of NF-κB. Preliminary studies from our lab demonstrated that overexpression of ALP led to decreased NF-κB activity by κB reporter assay and electrophoresis mobility gel shift assay (EMSA). The current project aims to further evaluate the role of ALP in the regulation of NF-κB signaling in CRC cells. We found that overexpression of ALP in human CRC HT29 cells greatly reduced both the number and the size of colonies that were formed in a soft agar assay. ALP overexpression also decreased the cell growth rate and cell migration ability, while shRNA mediated knockdown of ALP showed opposite effects, confirming that ALP is a tumor suppressor in CRC HT29 cells. Overexpression of ALP led to decreased NF-κB activity by κB reporter assay and condition media assay in CRC HT29 cells. Furthermore, immunohistochemical analysis with human colon vii tissues revealed that there is a gradual loss of ALP protein with tumor progression. We also found that ALP predominantly localizes in the cytoplasm, and binds to the p65 subunit of NF-κB, and might be functioning downstream of IκB kinase (IKK). In summary, in this study, we provide evidence regarding the tumor suppressor role of ALP in CRC by functioning as novel negative regulator of NF-κB. This discovery could lead to the establishment of ALP as a potential biomarker and therapeutic target in CRC.