1
|
Molecular Characteristics of Amyloid Precursor Protein (APP) and Its Effects in Cancer. Int J Mol Sci 2021; 22:ijms22094999. [PMID: 34066808 PMCID: PMC8125876 DOI: 10.3390/ijms22094999] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2021] [Revised: 05/02/2021] [Accepted: 05/06/2021] [Indexed: 12/16/2022] Open
Abstract
Amyloid precursor protein (APP) is a type 1 transmembrane glycoprotein, and its homologs amyloid precursor-like protein 1 (APLP1) and amyloid precursor-like protein 2 (APLP2) are highly conserved in mammals. APP and APLP are known to be intimately involved in the pathogenesis and progression of Alzheimer's disease and to play important roles in neuronal homeostasis and development and neural transmission. APP and APLP are also expressed in non-neuronal tissues and are overexpressed in cancer cells. Furthermore, research indicates they are involved in several cancers. In this review, we examine the biological characteristics of APP-related family members and their roles in cancer.
Collapse
|
2
|
Galinato M, Shimoda K, Aguiar A, Hennig F, Boffelli D, McVoy MA, Hertel L. Single-Cell Transcriptome Analysis of CD34 + Stem Cell-Derived Myeloid Cells Infected With Human Cytomegalovirus. Front Microbiol 2019; 10:577. [PMID: 30949159 PMCID: PMC6437045 DOI: 10.3389/fmicb.2019.00577] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Accepted: 03/06/2019] [Indexed: 12/18/2022] Open
Abstract
Myeloid cells are important sites of lytic and latent infection by human cytomegalovirus (CMV). We previously showed that only a small subset of myeloid cells differentiated from CD34+ hematopoietic stem cells is permissive to CMV replication, underscoring the heterogeneous nature of these populations. The exact identity of resistant and permissive cell types, and the cellular features characterizing the latter, however, could not be dissected using averaging transcriptional analysis tools such as microarrays and, hence, remained enigmatic. Here, we profile the transcriptomes of ∼7000 individual cells at day 1 post-infection using the 10× genomics platform. We show that viral transcripts are detectable in the majority of the cells, suggesting that virion entry is unlikely to be the main target of cellular restriction mechanisms. We further show that viral replication occurs in a small but specific sub-group of cells transcriptionally related to, and likely derived from, a cluster of cells expressing markers of Colony Forming Unit – Granulocyte, Erythrocyte, Monocyte, Megakaryocyte (CFU-GEMM) oligopotent progenitors. Compared to the remainder of the population, CFU-GEMM cells are enriched in transcripts with functions in mitochondrial energy production, cell proliferation, RNA processing and protein synthesis, and express similar or higher levels of interferon-related genes. While expression levels of the former are maintained in infected cells, the latter are strongly down-regulated. We thus propose that the preferential infection of CFU-GEMM cells may be due to the presence of a pre-established pro-viral environment, requiring minimal optimization efforts from viral effectors, rather than to the absence of specific restriction factors. Together, these findings identify a potentially new population of myeloid cells permissive to CMV replication, and provide a possible rationale for their preferential infection.
Collapse
Affiliation(s)
- Melissa Galinato
- Center for Immunobiology and Vaccine Development, Children's Hospital Oakland Research Institute, Oakland, CA, United States
| | - Kristen Shimoda
- Center for Immunobiology and Vaccine Development, Children's Hospital Oakland Research Institute, Oakland, CA, United States
| | - Alexis Aguiar
- Center for Immunobiology and Vaccine Development, Children's Hospital Oakland Research Institute, Oakland, CA, United States
| | - Fiona Hennig
- Center for Genetics, Children's Hospital Oakland Research Institute, Oakland, CA, United States
| | - Dario Boffelli
- Center for Genetics, Children's Hospital Oakland Research Institute, Oakland, CA, United States
| | - Michael A McVoy
- Department of Pediatrics, Virginia Commonwealth University, Richmond, VA, United States
| | - Laura Hertel
- Center for Immunobiology and Vaccine Development, Children's Hospital Oakland Research Institute, Oakland, CA, United States
| |
Collapse
|
3
|
Sliker BH, Goetz BT, Peters HL, Poelaert BJ, Borgstahl GEO, Solheim JC. Beta 2-microglobulin regulates amyloid precursor-like protein 2 expression and the migration of pancreatic cancer cells. Cancer Biol Ther 2019; 20:931-940. [PMID: 30810435 DOI: 10.1080/15384047.2019.1580414] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Beta 2-microglobulin (β2m) is a component of the major histocompatibility complex (MHC) class I molecule, which presents tumor antigens to T lymphocytes to trigger cancer cell destruction. Notably, β2m has been reported as persistently expressed, rather than down regulated, in some tumor types. For renal cell and oral squamous cell carcinomas, β2m expression has been linked to increased migratory capabilities. The migratory ability of pancreatic cancer cells contributes to their metastatic tendencies and lethal nature. Therefore, in this study, we examined the impact of β2m on pancreatic cancer cell migration. We found that β2m protein is amply expressed in several human pancreatic cancer cell lines (S2-013, PANC-1, and MIA PaCa-2). Reducing β2m expression by short interfering RNA (siRNA) transfection significantly slowed the migration of the PANC-1 and S2-013 cancer cell lines, but increased the migration of the MIA PaCa-2 cell line. The amyloid precursor-like protein 2 (APLP2) has been documented as contributing to pancreatic cancer cell migration, invasiveness, and metastasis. We have previously shown that β2m/HLA class I/peptide complexes associate with APLP2 in S2-013 cells, and in this study we also detected their association in PANC-1 cells but not MIA PaCa-2 cells. In addition, siRNA down regulation of β2m expression diminished the expression of APLP2 in S2-013 and PANC-1 but heightened the level of APLP2 in MIA PaCa-2 cells, consistent with our migration data and co-immunoprecipitation data. Thus, our findings indicate that β2m regulates pancreatic cancer cell migration, and furthermore suggest that APLP2 is an intermediary in this process.
Collapse
Affiliation(s)
- Bailee H Sliker
- a Eppley Institute for Research in Cancer and Allied Diseases , University of Nebraska Medical Center , Omaha , NE , USA.,b Fred and Pamela Buffett Cancer Center , University of Nebraska Medical Center , Omaha , NE , USA
| | - Benjamin T Goetz
- a Eppley Institute for Research in Cancer and Allied Diseases , University of Nebraska Medical Center , Omaha , NE , USA.,b Fred and Pamela Buffett Cancer Center , University of Nebraska Medical Center , Omaha , NE , USA
| | - Haley L Peters
- a Eppley Institute for Research in Cancer and Allied Diseases , University of Nebraska Medical Center , Omaha , NE , USA.,b Fred and Pamela Buffett Cancer Center , University of Nebraska Medical Center , Omaha , NE , USA
| | - Brittany J Poelaert
- a Eppley Institute for Research in Cancer and Allied Diseases , University of Nebraska Medical Center , Omaha , NE , USA.,b Fred and Pamela Buffett Cancer Center , University of Nebraska Medical Center , Omaha , NE , USA
| | - Gloria E O Borgstahl
- a Eppley Institute for Research in Cancer and Allied Diseases , University of Nebraska Medical Center , Omaha , NE , USA.,b Fred and Pamela Buffett Cancer Center , University of Nebraska Medical Center , Omaha , NE , USA.,c Department of Biochemistry and Molecular Biology , University of Nebraska Medical Center , Omaha , NE , USA.,d Department of Pharmaceutical Sciences , University of Nebraska Medical Center , Omaha , NE , USA
| | - Joyce C Solheim
- a Eppley Institute for Research in Cancer and Allied Diseases , University of Nebraska Medical Center , Omaha , NE , USA.,b Fred and Pamela Buffett Cancer Center , University of Nebraska Medical Center , Omaha , NE , USA.,c Department of Biochemistry and Molecular Biology , University of Nebraska Medical Center , Omaha , NE , USA.,e Department of Pathology and Microbiology , University of Nebraska Medical Center , Omaha , NE , USA
| |
Collapse
|
4
|
Amyloid precursor protein and amyloid precursor-like protein 2 in cancer. Oncotarget 2017; 7:19430-44. [PMID: 26840089 PMCID: PMC4991393 DOI: 10.18632/oncotarget.7103] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Accepted: 01/23/2016] [Indexed: 12/22/2022] Open
Abstract
Amyloid precursor protein (APP) and its family members amyloid precursor-like protein 1 (APLP1) and amyloid precursor-like protein 2 (APLP2) are type 1 transmembrane glycoproteins that are highly conserved across species. The transcriptional regulation of APP and APLP2 is similar but not identical, and the cleavage of both proteins is regulated by phosphorylation. APP has been implicated in Alzheimer's disease causation, and in addition to its importance in neurology, APP is deregulated in cancer cells. APLP2 is likewise overexpressed in cancer cells, and APLP2 and APP are linked to increased tumor cell proliferation, migration, and invasion. In this present review, we discuss the unfolding account of these APP family members’ roles in cancer progression and metastasis.
Collapse
|
5
|
Peters HL, Yan Y, Solheim JC. APLP2 regulates the expression of MHC class I molecules on irradiated Ewing's sarcoma cells. Oncoimmunology 2013; 2:e26293. [PMID: 24353913 PMCID: PMC3862638 DOI: 10.4161/onci.26293] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2013] [Revised: 08/27/2013] [Accepted: 08/27/2013] [Indexed: 01/06/2023] Open
Abstract
Ewing's sarcoma (EWS) is a pediatric cancer that is conventionally treated by surgery, chemotherapy, and radiation therapy. Innovative immunotherapies to treat EWS are currently under development. Unfortunately for EWS patients, when the disease is found to be resistant to current therapeutic approaches, the prognosis is predictably grim. Radiation therapy and immunotherapy could potentially synergize in the eradication of EWS, as some studies have previously shown that irradiation increases the presence of immune receptors, including MHC class I molecules, on the surface of tumor cells. However, EWS cells have been reported to express low levels of MHC class I molecules, a phenotype that would inhibit T-cell mediated lysis. We have previously demonstrated that the transgene-driven overexpression of amyloid β (A4) precursor-like protein 2 (APLP2) reduces the expression of MHC class I molecules on the surface of human cervical carcinoma HeLa cells. We thus examined whether endogenously expressed APLP2 downregulates MHC class I expression on EWS cells, particularly upon irradiation. We found that irradiation induces the relocalization of APLP2 and MHC class I molecules on the surface of EWS cells, redistributing cells from subpopulations with relatively low APLP2 and high MHC class I into subpopulations with relatively high APLP2 and low MHC class I surface expression. Consistent with these findings, the transfection of an APLP2-targeting siRNA into EWS cells increased MHC class I expression on the cell surface. Furthermore, APLP2 was found by co-immunoprecipitation to bind to MHC class I molecules. Taken together, these findings suggest that APLP2 inhibits MHC class I expression on the surface of irradiated EWS cells by a mechanism that involves APLP2/MHC class I interactions. Thus, therapeutic strategies that limit APLP2 expression may boost the ability of T cells to recognize and eradicate EWS in patients.
Collapse
Affiliation(s)
- Haley L Peters
- Eppley Institute; University of Nebraska Medical Center; Omaha, NE USA
| | - Ying Yan
- Eppley Institute; University of Nebraska Medical Center; Omaha, NE USA
| | - Joyce C Solheim
- Eppley Institute; University of Nebraska Medical Center; Omaha, NE USA ; Department of Biochemistry and Molecular Biology; University of Nebraska Medical Center; Omaha, NE USA ; Department of Pathology and Microbiology; University of Nebraska Medical Center; Omaha, NE USA
| |
Collapse
|
6
|
Peters HL, Tuli A, Wang X, Liu C, Pan Z, Ouellette MM, Hollingsworth MA, Macdonald RG, Solheim JC. Relevance of amyloid precursor-like protein 2 C-terminal fragments in pancreatic cancer cells. Int J Oncol 2012; 41:1464-74. [PMID: 22797723 PMCID: PMC3482291 DOI: 10.3892/ijo.2012.1553] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2012] [Accepted: 05/25/2012] [Indexed: 12/21/2022] Open
Abstract
In some cellular systems, particularly neurons, amyloid precursor-like protein 2 (APLP2), and its highly homologous family member amyloid precursor protein (APP), have been linked to cellular growth. APLP2 and APP undergo regulated intramembrane proteolysis to produce C-terminal fragments. In this study, we found comprehensive expression of APLP2 C-terminal fragments in a panel of pancreatic cancer cell lines; however, APP C-terminal fragments were notably limited to the BxPC3 cell line. Extensive glycosaminoglycan modification on APLP2 was also found in the majority of pancreatic cancer cell lines. Glycosaminoglycan-modified and -unmodified APLP2, and particularly APLP2 C-terminal fragments, also demonstrated increased expression in oncogene-transformed pancreatic ductal cells. Additionally, elevated APLP2 levels were confirmed in human pancreatic cancer tissue. Downregulation of APLP2 and APP expression, alone or in combination, caused a decrease in the growth of a pancreatic cancer cell line with representatively low APP C-terminal fragment expression, the S2-013 cell line. Furthermore, we found that treatment with β-secretase inhibitors to block formation of APLP2 C-terminal fragments decreased the growth and viability of S2-013 cells, without affecting the survival of a non-transformed pancreatic ductal cell line. In conclusion, our studies demonstrate that abundant APLP2, but not APP, C-terminal fragment expression is conserved in pancreatic cancer cell lines; however, APP and APLP2 equally regulated the growth of S2-013 pancreatic cancer cells. Chiefly, our discoveries establish a role for APLP2 in the growth of pancreatic cancer cells and show that inhibitors preventing APLP2 cleavage reduce the viability of pancreatic cancer cells.
Collapse
Affiliation(s)
- Haley L Peters
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
7
|
Peters HL, Tuli A, Sharma M, Naslavsky N, Caplan S, MacDonald RG, Solheim JC. Regulation of major histocompatibility complex class I molecule expression on cancer cells by amyloid precursor-like protein 2. Immunol Res 2012; 51:39-44. [PMID: 21826533 DOI: 10.1007/s12026-011-8238-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The three members of the amyloid precursor protein family in mammals [amyloid precursor protein, amyloid precursor-like protein 1, and amyloid precursor-like protein 2 (APLP2)] have been implicated in a large array of intracellular processes, which include development, transcription, apoptosis, metabolism, and the cell cycle. A series of studies by our laboratories has demonstrated that APLP2 is highly expressed by many cancer cell lines (with the highest expression in pancreatic cancer cell lines) and that it facilitates major histocompatibility complex (MHC) class I molecule endocytosis. This review focuses on this recently revealed function of APLP2 relevant to tumor immunology: that it acts as a novel regulator of MHC class I molecule surface expression.
Collapse
Affiliation(s)
- Haley L Peters
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | | | | | | | | | | | | |
Collapse
|
8
|
Tuli A, Sharma M, Capek HL, Naslavsky N, Caplan S, Solheim JC. Mechanism for amyloid precursor-like protein 2 enhancement of major histocompatibility complex class I molecule degradation. J Biol Chem 2009; 284:34296-307. [PMID: 19808674 DOI: 10.1074/jbc.m109.039727] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Earlier studies have demonstrated interaction of the murine major histocompatibility complex (MHC) class I molecule K(d) with amyloid precursor-like protein 2 (APLP2), a ubiquitously expressed member of the amyloid precursor protein family. Our current findings indicate that APLP2 is internalized in a clathrin-dependent manner, as shown by utilization of inhibitors of the clathrin pathway. Furthermore, we demonstrated that APLP2 and K(d) bind at the cell surface and are internalized together. The APLP2 cytoplasmic tail contains two overlapping consensus motifs for binding to the adaptor protein-2 complex, and mutation of a tyrosine shared by both motifs severely impaired APLP2 internalization and ability to promote K(d) endocytosis. Upon increased expression of wild type APLP2, K(d) molecules were predominantly directed to the lysosomes rather than recycled to the plasma membrane. These findings suggest a model in which APLP2 binds K(d) at the plasma membrane, facilitates uptake of K(d) in a clathrin-dependent manner, and routes the endocytosed K(d) to the lysosomal degradation pathway. Thus, APLP2 has a multistep trafficking function that influences the expression of major histocompatibility complex class I molecules at the plasma membrane.
Collapse
Affiliation(s)
- Amit Tuli
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, Nebraska 68198-6805, USA
| | | | | | | | | | | |
Collapse
|
9
|
Tuli A, Sharma M, Wang X, Simone LC, Capek HL, Cate S, Hildebrand WH, Naslavsky N, Caplan S, Solheim JC. Amyloid precursor-like protein 2 association with HLA class I molecules. Cancer Immunol Immunother 2009; 58:1419-31. [PMID: 19184004 DOI: 10.1007/s00262-009-0657-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2008] [Accepted: 01/02/2009] [Indexed: 01/18/2023]
Abstract
Amyloid precursor-like protein 2 (APLP2) is a ubiquitously expressed protein. The previously demonstrated functions for APLP2 include binding to the mouse major histocompatibility complex (MHC) class I molecule H-2K(d) and down regulating its cell surface expression. In this study, we have investigated the interaction of APLP2 with the human leukocyte antigen (HLA) class I molecule in human tumor cell lines. APLP2 was readily detected in pancreatic, breast, and prostate tumor lines, although it was found only in very low amounts in lymphoma cell lines. In a pancreatic tumor cell line, HLA class I was extensively co-localized with APLP2 in vesicular compartments following endocytosis of HLA class I molecules. In pancreatic, breast, and prostate tumor lines, APLP2 was bound to the HLA class I molecule. APLP2 was found to bind to HLA-A24, and more strongly to HLA-A2. Increased expression of APLP2 resulted in reduced surface expression of HLA-A2 and HLA-A24. Overall, these studies demonstrate that APLP2 binds to the HLA class I molecule, co-localizes with it in intracellular vesicles, and reduces the level of HLA class I molecule cell surface expression.
Collapse
Affiliation(s)
- Amit Tuli
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, NE, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
10
|
Tuli A, Sharma M, McIlhaney MM, Talmadge JE, Naslavsky N, Caplan S, Solheim JC. Amyloid precursor-like protein 2 increases the endocytosis, instability, and turnover of the H2-K(d) MHC class I molecule. THE JOURNAL OF IMMUNOLOGY 2008; 181:1978-87. [PMID: 18641335 DOI: 10.4049/jimmunol.181.3.1978] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The defense against the invasion of viruses and tumors relies on the presentation of viral and tumor-derived peptides to CTL by cell surface MHC class I molecules. Previously, we showed that the ubiquitously expressed protein amyloid precursor-like protein 2 (APLP2) associates with the folded form of the MHC class I molecule K(d). In the current study, APLP2 was found to associate with folded K(d) molecules following their endocytosis and to increase the amount of endocytosed K(d). In addition, increased expression of APLP2 was shown to decrease K(d) surface expression and thermostability. Correspondingly, K(d) thermostability and surface expression were increased by down-regulation of APLP2 expression. Overall, these data suggest that APLP2 modulates the stability and endocytosis of K(d) molecules.
Collapse
Affiliation(s)
- Amit Tuli
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | | | | | | | | | | | | |
Collapse
|