scholarly journals Functional Roles of SPINK1 in Cancers

2021 ◽  
Vol 22 (8) ◽  
pp. 3814
Author(s):  
Tsung-Chieh Lin
Keyword(s):  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Cancer Progression ◽  
Biological Effects ◽  
Growth Factor Receptor ◽  
Clinical Information ◽  
Structural Similarity ◽  
Cell Types ◽  
Cancer Proliferation ◽  
Epidermal Growth

Serine Peptidase Inhibitor Kazal Type 1 (SPINK1) is a secreted protein known as a protease inhibitor of trypsin in the pancreas. However, emerging evidence shows its function in promoting cancer progression in various types of cancer. SPINK1 modulated tumor malignancies and induced the activation of the downstream signaling of epidermal growth factor receptor (EGFR) in cancer cells, due to the structural similarity with epidermal growth factor (EGF). The discoverable SPINK1 somatic mutations, expressional signatures, and prognostic significances in various types of cancer have attracted attention as a cancer biomarker in clinical applications. Emerging findings further clarify the direct and indirect biological effects of SPINK1 in regulating cancer proliferation, metastasis, drug resistance, transdifferentiation, and cancer stemness, warranting the exploration of the SPINK1-mediated molecular mechanism to identify a therapeutic strategy. In this review article, we first integrate the transcriptomic data of different types of cancer with clinical information and recent findings of SPINK1-mediated malignant phenotypes. In addition, a comprehensive summary of SPINK1 expression in a pan-cancer panel and individual cell types of specific organs at the single-cell level is presented to indicate the potential sites of tumorigenesis, which has not yet been reported. This review aims to shed light on the roles of SPINK1 in cancer and provide guidance and potential directions for scientists in this field.

An epidermal growth factor receptor/ret chimera generates mitogenic and transforming signals: evidence for a ret-specific signaling pathway

1994 ◽  
Vol 14 (1) ◽  
pp. 663-675
Author(s):  
M Santoro ◽  
W T Wong ◽  
P Aroca ◽  
E Santos ◽  
B Matoskova ◽  
...  
Keyword(s):  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Tyrosine Kinases ◽  
Mammalian Cells ◽  
Egf Receptor ◽  
Biological Effects ◽  
Ectopic Expression ◽  
Growth Factor Receptor ◽  
Dependent Signal ◽  
Epidermal Growth

A chimeric expression vector which encoded for a molecule encompassing the extracellular domain of the epidermal growth factor (EGF) receptor (EGFR) and the intracellular domain of the ret kinase (EGFR/ret chimera) was generated. Upon ectopic expression in mammalian cells, the EGFR/ret chimera was correctly synthesized and transported to the cell surface, where it was shown capable of binding EGF and transducing an EGF-dependent signal intracellularly. Thus, the EGFR/ret chimera allows us to study the biological effects and biochemical activities of the ret kinase under controlled conditions of activation. Comparative analysis of the growth-promoting activity of the EGFR/ret chimera expressed in fibroblastic or hematopoietic cells revealed a biological phenotype clearly distinguishable from that of the EGFR, indicating that the two kinases couple with mitogenic pathways which are different to some extent. Analysis of biochemical pathways implicated in the transduction of mitogenic signals also evidenced significant differences between the ret kinase and other receptor tyrosine kinases. Thus, the sum of our results indicates the existence of a ret-specific pathway of mitogenic signaling.

scholarly journals Current Understanding of the Emerging Role of Prolidase in Cellular Metabolism

2020 ◽  
Vol 21 (16) ◽  
pp. 5906 ◽  
Author(s):  
Magdalena Misiura ◽  
Wojciech Miltyk
Keyword(s):  
Epidermal Growth Factor Receptor ◽  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Intracellular Signaling ◽  
Transforming Growth Factor ◽  
Biological Effects ◽  
Growth Factor Receptor ◽  
Cellular Metabolism ◽  
Interferon Α ◽  
Epidermal Growth

Prolidase [EC 3.4.13.9], known as PEPD, cleaves di- and tripeptides containing carboxyl-terminal proline or hydroxyproline. For decades, prolidase has been thoroughly investigated, and several mechanisms regulating its activity are known, including the activation of the β1-integrin receptor, insulin-like growth factor 1 receptor (IGF-1) receptor, and transforming growth factor (TGF)-β1 receptor. This process may result in increased availability of proline in the mitochondrial proline cycle, thus making proline serve as a substrate for the resynthesis of collagen, an intracellular signaling molecule. However, as a ligand, PEPD can bind directly to the epidermal growth factor receptor (EGFR, epidermal growth factor receptor 2 (HER2)) and regulate cellular metabolism. Recent reports have indicated that PEPD protects p53 from uncontrolled p53 subcellular activation and its translocation between cellular compartments. PEPD also participates in the maturation of the interferon α/β receptor by regulating its expression. In addition to the biological effects, prolidase demonstrates clinical significance reflected in the disease known as prolidase deficiency. It is also known that prolidase activity is affected in collagen metabolism disorders, metabolic, and oncological conditions. In this article, we review the latest knowledge about prolidase and highlight its biological function, and thus provide an in-depth understanding of prolidase as a dipeptidase and protein regulating the function of key biomolecules in cellular metabolism.

Signaling from germ cells mediated by therhomboidhomologstetorganizes encapsulation by somatic support cells

Development ◽  
2002 ◽  
Vol 129 (19) ◽  
pp. 4523-4534 ◽  
Author(s):  
Cordula Schulz ◽  
Cricket G. Wood ◽  
D. Leanne Jones ◽  
Salli I. Tazuke ◽  
Margaret T. Fuller
Keyword(s):  
Epidermal Growth Factor Receptor ◽  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Germ Cells ◽  
Somatic Cells ◽  
Growth Factor Receptor ◽  
Cell Types ◽  
Germ Cell Differentiation ◽  
Epidermal Growth ◽  
Set Up

Germ cells normally differentiate in the context of encapsulating somatic cells. However, the mechanisms that set up the special relationship between germ cells and somatic support cells and the signals that mediate the crucial communications between the two cell types are poorly understood. We show that interactions between germ cells and somatic support cells in Drosophila depend on wild-type function of the stet gene. In males, stet acts in germ cells to allow their encapsulation by somatic cyst cells and is required for germ cell differentiation. In females, stet function allows inner sheath cells to enclose early germ cells correctly at the tip of the germarium. stet encodes a homolog of rhomboid, a component of the epidermal growth factor receptor signaling pathway involved in ligand activation in the signaling cell. The stet mutant phenotype suggests that stet facilitates signaling from germ cells to the epidermal growth factor receptor on somatic cells, resulting in the encapsulation of germ cells by somatic support cells. The micro-environment provided by the surrounding somatic cells may, in turn, regulate differentiation of the germ cells they enclose.

Subfractionation of the endocytic pathway: isolation of compartments involved in the processing of internalised epidermal growth factor-receptor complexes

1989 ◽  
Vol 94 (4) ◽  
pp. 685-694
Author(s):  
C.E. Futter ◽  
C.R. Hopkins
Keyword(s):  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Egf Receptor ◽  
Biological Effects ◽  
Growth Factor Receptor ◽  
Endocytic Pathway ◽  
Receptor Complexes ◽  
Epidermal Growth ◽  
Endocytic Vesicles ◽  
Different Parts

The aim of the present study was to isolate different parts of the endocytic pathway in order to examine the role of epidermal growth factor (EGF)-receptor internalisation in mediating the biological effects of EGF. We have used an antibody to the transferrin receptor complexed with colloidal gold to modify the density of the endocytic compartments so that they can be purified by sucrose density centrifugation. Using this technique, we have been able to isolate a highly purified preparation of endocytic vesicles from H.Ep.2 cells that contain internalised EGF. By employing pulse—chase protocols, it is possible to isolate the different parts of the endocytic pathway and show that they are temporally distinct with regard to the processing of EGF. It should now be possible to examine interactions between the EGF receptor and intracellular substrates in different parts of the endocytic pathway.

scholarly journals Positive and negative tissue-specific signaling by a nematode epidermal growth factor receptor.

1997 ◽  
Vol 8 (5) ◽  
pp. 779-793 ◽  
Author(s):  
G M Lesa ◽  
P W Sternberg
Keyword(s):  
Epidermal Growth Factor Receptor ◽  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Binding Sites ◽  
Growth Factor Receptor ◽  
Cell Types ◽  
Negative Regulation ◽  
Tissue Specific ◽  
Epidermal Growth

The major determinants of receptor tissue tyrosine kinase (RTK) signaling specificity have been proposed to be Src homology 2 (SH2) binding sites, phosphotyrosine-containing oligopeptides in the cytoplasmic domain of the receptor. The Caenorhabditis elegans epidermal growth factor receptor homologue LET-23 has multiple functions during development and has eight potential SH2-binding sites in a region carboxyl terminal to its kinase domain. By analyzing transgenic nematodes for three distinct LET-23 functions, we show that six of eight potential sites function in vivo and that they are required for most, but not all, of LET-23 activity. A single site is necessary and sufficient to promote wild-type fertility. Three other sites activate the RAS pathway and are involved only in viability and vulval differentiation. A fifth site is promiscuous and can mediate all three LET-23 functions. An additional site mediates tissue-specific negative regulation. Putative SH2 binding sites are thus key effectors of both cell-specific and negative regulation in an intact organism. We suggest two distinct mechanisms for tissue-specific RTK-mediated signaling. A positive mechanism would promote RTK function through effectors present only in certain cell types. A negative mechanism would inhibit RTK function through tissue-specific negative regulators.

scholarly journals The Kinetics of Mannose 6-Phosphate Receptor Trafficking in the Endocytic Pathway in HEp-2 Cells: The Receptor Enters and Rapidly Leaves Multivesicular Endosomes without Accumulating in a Prelysosomal Compartment

1998 ◽  
Vol 9 (4) ◽  
pp. 809-816 ◽  
Author(s):  
Jennifer Hirst ◽  
Clare E. Futter ◽  
Colin R. Hopkins
Keyword(s):  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Growth Factor Receptor ◽  
Cell Types ◽  
Endocytic Pathway ◽  
Receptor Complexes ◽  
Epidermal Growth ◽  
Mannose 6 Phosphate ◽  
Golgi Network ◽  
Multivesicular Endosomes

We have previously shown that in HEp-2 cells, multivesicular bodies (MVBs) processing internalized epidermal growth factor–epidermal growth factor receptor complexes mature and fuse directly with lysosomes in which the complexes are degraded. The MVBs do not fuse with a prelysosomal compartment enriched in mannose 6-phosphate receptor (M6PR) as has been described in other cell types. Here we show that the cation-independent M6PR does not become enriched in the endocytic pathway en route to the lysosome, but if a pulse of M6PR or an M6PR ligand, cathepsin D, is followed, a significant fraction of these proteins are routed from the trans-Golgi to MVBs. Accumulation of M6PR does not occur because when the ligand dissociates, the receptor rapidly leaves the MVB. At steady state, most M6PR are distributed within the trans-Golgi andtrans-Golgi network and in vacuolar structures distributed in the peripheral cytoplasm. We suggest that these M6PR-rich vacuoles are on the return route from MVBs to thetrans-Golgi network and that a separate stable M6PR-rich compartment equivalent to the late endosome/prelysosome stage does not exist on the endosome–lysosome pathway in these cells.

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