The epidermal growth factor receptor (EGFR; ErbB-1; HER1 in humans) is a
transmembrane protein
A transmembrane protein (TP) is a type of integral membrane protein that spans the entirety of the cell membrane. Many transmembrane proteins function as gateways to permit the transport of specific substances across the membrane. They frequentl ...
that is a
receptor
Receptor may refer to:
* Sensory receptor, in physiology, any structure which, on receiving environmental stimuli, produces an informative nerve impulse
*Receptor (biochemistry), in biochemistry, a protein molecule that receives and responds to a ...
for members of the
epidermal growth factor
Epidermal growth factor (EGF) is a protein that stimulates cell growth and differentiation by binding to its receptor, EGFR. Human EGF is 6-k Da and has 53 amino acid residues and three intramolecular disulfide bonds.
EGF was originally descr ...
family (EGF family) of
extracellular
This glossary of biology terms is a list of definitions of fundamental terms and concepts used in biology, the study of life and of living organisms. It is intended as introductory material for novices; for more specific and technical definitions ...
protein
ligands
In coordination chemistry, a ligand is an ion or molecule (functional group) that binds to a central metal atom to form a coordination complex. The bonding with the metal generally involves formal donation of one or more of the ligand's electro ...
.
The epidermal growth factor receptor is a member of the
ErbB family of receptors, a subfamily of four closely related
receptor tyrosine kinase
Receptor tyrosine kinases (RTKs) are the high-affinity cell surface receptors for many polypeptide growth factors, cytokines, and hormones. Of the 90 unique tyrosine kinase genes identified in the human genome, 58 encode receptor tyrosine kinase ...
s: EGFR (ErbB-1),
HER2/neu
Receptor tyrosine-protein kinase erbB-2 is a protein that in humans is encoded by the ''ERBB2'' gene. ERBB is abbreviated from erythroblastic oncogene B, a gene originally isolated from the avian genome. The human protein is also frequently refer ...
(ErbB-2),
Her 3 (ErbB-3) and
Her 4
Receptor tyrosine-protein kinase erbB-4 is an enzyme that in humans is encoded by the ''ERBB4'' gene. Alternatively spliced variants that encode different protein isoforms have been described; however, not all variants have been fully characterized ...
(ErbB-4). In many cancer types, mutations affecting EGFR expression or activity could result in
cancer
Cancer is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body. These contrast with benign tumors, which do not spread. Possible signs and symptoms include a lump, abnormal b ...
.
Epidermal growth factor and its receptor was discovered by
Stanley Cohen of
Vanderbilt University
Vanderbilt University (informally Vandy or VU) is a private research university in Nashville, Tennessee. Founded in 1873, it was named in honor of shipping and rail magnate Cornelius Vanderbilt, who provided the school its initial $1-million ...
. Cohen shared the 1986
Nobel Prize in Medicine
The Nobel Prize in Physiology or Medicine is awarded yearly by the Nobel Assembly at the Karolinska Institute for outstanding discoveries in physiology or medicine. The Nobel Prize is not a single prize, but five separate prizes that, according ...
with
Rita Levi-Montalcini
Rita Levi-Montalcini (, ; 22 April 1909 – 30 December 2012) was an Italian Nobel laureate, honored for her work in neurobiology. She was awarded the 1986 Nobel Prize in Physiology or Medicine jointly with colleague Stanley Cohen for the ...
for their discovery of
growth factor
A growth factor is a naturally occurring substance capable of stimulating cell proliferation, wound healing, and occasionally cellular differentiation. Usually it is a secreted protein or a steroid hormone. Growth factors are important for regu ...
s.
Deficient signaling of the EGFR and other
receptor tyrosine kinase
Receptor tyrosine kinases (RTKs) are the high-affinity cell surface receptors for many polypeptide growth factors, cytokines, and hormones. Of the 90 unique tyrosine kinase genes identified in the human genome, 58 encode receptor tyrosine kinase ...
s in humans is associated with diseases such as Alzheimer's, while over-expression is associated with the development of a wide variety of tumors. Interruption of EGFR signalling, either by blocking EGFR binding sites on the extracellular domain of the receptor or by inhibiting intracellular tyrosine kinase activity, can prevent the growth of EGFR-expressing tumours and improve the patient's condition.
Function
Epidermal growth factor receptor (EGFR) is a
transmembrane protein
A transmembrane protein (TP) is a type of integral membrane protein that spans the entirety of the cell membrane. Many transmembrane proteins function as gateways to permit the transport of specific substances across the membrane. They frequentl ...
that is activated by binding of its specific
ligand
In coordination chemistry, a ligand is an ion or molecule (functional group) that binds to a central metal atom to form a coordination complex. The bonding with the metal generally involves formal donation of one or more of the ligand's electr ...
s, including
epidermal growth factor
Epidermal growth factor (EGF) is a protein that stimulates cell growth and differentiation by binding to its receptor, EGFR. Human EGF is 6-k Da and has 53 amino acid residues and three intramolecular disulfide bonds.
EGF was originally descr ...
and
transforming growth factor α
Transforming growth factor alpha (TGF-α) is a protein that in humans is encoded by the TGFA gene. As a member of the epidermal growth factor (EGF) family, TGF-α is a mitogenic polypeptide. The protein becomes activated when binding to receptors c ...
(TGFα). ErbB2 has no known direct activating
ligand
In coordination chemistry, a ligand is an ion or molecule (functional group) that binds to a central metal atom to form a coordination complex. The bonding with the metal generally involves formal donation of one or more of the ligand's electr ...
, and may be in an activated state constitutively or become active upon
heterodimerization
In biochemistry, a protein dimer is a macromolecular complex formed by two protein monomers, or single proteins, which are usually non-covalently bound. Many macromolecules, such as proteins or nucleic acids, form dimers. The word ''dimer'' has ...
with other family members such as EGFR.
Upon activation by its growth factor ligands, EGFR undergoes a transition from an inactive
monomer
In chemistry, a monomer ( ; ''mono-'', "one" + '' -mer'', "part") is a molecule that can react together with other monomer molecules to form a larger polymer chain or three-dimensional network in a process called polymerization.
Classification
Mo ...
ic form to an active
homodimer
In biochemistry, a protein dimer is a macromolecular complex formed by two protein monomers, or single proteins, which are usually non-covalently bound. Many macromolecules, such as proteins or nucleic acids, form dimers. The word ''dimer'' ha ...
.
– although there is some evidence that preformed inactive dimers may also exist before ligand binding. In addition to forming homodimers after ligand binding, EGFR may pair with another member of the ErbB receptor family, such as
ErbB2/Her2/neu, to create an activated
heterodimer
In biochemistry, a protein dimer is a macromolecular complex formed by two protein monomers, or single proteins, which are usually non-covalently bound. Many macromolecules, such as proteins or nucleic acids, form dimers. The word ''dimer'' has ...
. There is also evidence to suggest that clusters of activated EGFRs form, although it remains unclear whether this clustering is important for activation itself or occurs subsequent to activation of individual dimers.
EGFR dimerization stimulates its intrinsic intracellular protein-tyrosine kinase activity. As a result,
autophosphorylation
Autophosphorylation is a type of post-translational modification of proteins. It is generally defined as the phosphorylation of the kinase by itself. In eukaryotes, this process occurs by the addition of a phosphate group to serine, threonine or ...
of several
tyrosine
-Tyrosine or tyrosine (symbol Tyr or Y) or 4-hydroxyphenylalanine is one of the 20 standard amino acids that are used by cells to synthesize proteins. It is a non-essential amino acid with a polar side group. The word "tyrosine" is from the Gr ...
(Y) residues in the C-terminal
domain
Domain may refer to:
Mathematics
*Domain of a function, the set of input values for which the (total) function is defined
**Domain of definition of a partial function
**Natural domain of a partial function
**Domain of holomorphy of a function
* Do ...
of EGFR occurs. These include Y992, Y1045, Y1068, Y1148 and Y1173, as shown in the adjacent diagram.
This autophosphorylation elicits downstream activation and signaling by several other proteins that associate with the phosphorylated tyrosines through their own phosphotyrosine-binding
SH2 domain
The SH2 (Src Homology 2) domain is a structurally conserved protein domain contained within the Src oncoprotein and in many other intracellular signal-transducing proteins. SH2 domains allow proteins containing those domains to dock to phosphory ...
s. These downstream signaling proteins initiate several
signal transduction
Signal transduction is the process by which a chemical or physical signal is transmitted through a cell as a series of molecular events, most commonly protein phosphorylation catalyzed by protein kinases, which ultimately results in a cellula ...
cascades, principally the
MAPK
A mitogen-activated protein kinase (MAPK or MAP kinase) is a type of protein kinase that is specific to the amino acids serine and threonine (i.e., a serine/threonine-specific protein kinase). MAPKs are involved in directing cellular responses to ...
,
Akt
Protein kinase B (PKB), also known as Akt, is the collective name of a set of three serine/threonine-specific protein kinases that play key roles in multiple cellular processes such as glucose metabolism, apoptosis, cell proliferation, transc ...
and
JNK
c-Jun N-terminal kinases (JNKs), were originally identified as kinases that bind and phosphorylate c-Jun on Ser-63 and Ser-73 within its transcriptional activation domain. They belong to the mitogen-activated protein kinase family, and are ...
pathways, leading to
DNA synthesis
DNA synthesis is the natural or artificial creation of deoxyribonucleic acid (DNA) molecules. DNA is a macromolecule made up of nucleotide units, which are linked by covalent bonds and hydrogen bonds, in a repeating structure. DNA synthesis occur ...
and cell proliferation.
Such proteins modulate phenotypes such as
cell migration
Cell migration is a central process in the development and maintenance of multicellular organisms. Tissue formation during embryonic development, wound healing and immune responses all require the orchestrated movement of cells in particular dire ...
,
adhesion
Adhesion is the tendency of dissimilar particles or surfaces to cling to one another ( cohesion refers to the tendency of similar or identical particles/surfaces to cling to one another).
The forces that cause adhesion and cohesion can be ...
, and
proliferation. Activation of the receptor is important for the innate immune response in human skin. The kinase domain of EGFR can also cross-phosphorylate tyrosine residues of other receptors it is aggregated with, and can itself be activated in that manner.
Biological roles
The EGFR is essential for
ductal
Lafarge is a French industrial company specialising in cement, construction aggregates, and concrete. It is the world's largest cement manufacturer. It was founded in 1833 by Joseph-Auguste Pavin de Lafarge and is a part of the Holcim Group.
I ...
development of the
mammary gland
A mammary gland is an exocrine gland in humans and other mammals that produces milk to feed young offspring. Mammals get their name from the Latin word ''mamma'', "breast". The mammary glands are arranged in organs such as the breasts in primat ...
s,
and
agonist
An agonist is a chemical that activates a receptor to produce a biological response. Receptors are cellular proteins whose activation causes the cell to modify what it is currently doing. In contrast, an antagonist blocks the action of the ago ...
s of the EGFR such as
amphiregulin
Amphiregulin, also known as AREG, is a protein synthesized as a transmembrane glycoprotein with 252 aminoacids and it is encoded by the ''AREG'' gene. in humans.
Function
The protein encoded by this gene is a member of the epidermal growth fac ...
,
TGF-α, and heregulin induce both ductal and
lobuloalveolar
A mammary alveolus (plural: alveoli, from Latin ''alveolus'', "little cavity") is a small cavity or sac found in the mammary gland. Mammary alveoli are the site of milk production and storage in the mammary gland. Mammary alveoli cluster into g ...
development even in the absence of
estrogen
Estrogen or oestrogen is a category of sex hormone responsible for the development and regulation of the female reproductive system and secondary sex characteristics. There are three major endogenous estrogens that have estrogenic hormonal acti ...
and
progesterone
Progesterone (P4) is an endogenous steroid and progestogen sex hormone involved in the menstrual cycle, pregnancy, and embryogenesis of humans and other species. It belongs to a group of steroid hormones called the progestogens and is the m ...
.
Role in human disease
Cancer
Mutation
In biology, a mutation is an alteration in the nucleic acid sequence of the genome of an organism, virus, or extrachromosomal DNA. Viral genomes contain either DNA or RNA. Mutations result from errors during DNA or viral replication, mi ...
s that lead to EGFR overexpression (known as upregulation or amplification) have been associated with a number of
cancer
Cancer is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body. These contrast with benign tumors, which do not spread. Possible signs and symptoms include a lump, abnormal b ...
s, including
adenocarcinoma of the lung
Adenocarcinoma of the lung is the most common type of lung cancer, and like other forms of lung cancer, it is characterized by distinct cellular and molecular features. It is classified as one of several non-small cell lung cancers (NSCLC), to di ...
(40% of cases),
anal cancer
Anal cancer is a cancer which arises from the anus, the distal opening of the gastrointestinal tract. Symptoms may include bleeding from the anus or a lump near the anus. Other symptoms may include pain, itchiness, or discharge from the anus. ...
s,
glioblastoma
Glioblastoma, previously known as glioblastoma multiforme (GBM), is one of the most aggressive types of cancer that begin within the brain. Initially, signs and symptoms of glioblastoma are nonspecific. They may include headaches, personality ch ...
(50%) and
epithelian tumors of the head and neck (80–100%). These somatic mutations involving EGFR lead to its constant activation, which produces uncontrolled cell division.
In
glioblastoma
Glioblastoma, previously known as glioblastoma multiforme (GBM), is one of the most aggressive types of cancer that begin within the brain. Initially, signs and symptoms of glioblastoma are nonspecific. They may include headaches, personality ch ...
a specific mutation of EGFR, called EGFRvIII, is often observed.
Mutations, amplifications or misregulations of EGFR or family members are implicated in about 30% of all
epithelial
Epithelium or epithelial tissue is one of the four basic types of animal tissue, along with connective tissue, muscle tissue and nervous tissue. It is a thin, continuous, protective layer of compactly packed cells with a little intercellula ...
cancers.
Inflammatory disease
Aberrant EGFR signaling has been implicated in psoriasis, eczema and atherosclerosis.
However, its exact roles in these conditions are ill-defined.
Monogenic disease
A single child displaying multi-organ epithelial inflammation was found to have a homozygous loss of function mutation in the ''EGFR'' gene. The pathogenicity of the EGFR mutation was supported by in vitro experiments and functional analysis of a skin biopsy. His severe phenotype reflects many previous research findings into EGFR function. His clinical features included a papulopustular rash, dry skin, chronic diarrhoea, abnormalities of hair growth, breathing difficulties and electrolyte imbalances.
Wound healing and fibrosis
EGFR has been shown to play a critical role in
TGF-beta1 dependent
fibroblast
A fibroblast is a type of cell (biology), biological cell that synthesizes the extracellular matrix and collagen, produces the structural framework (Stroma (tissue), stroma) for animal Tissue (biology), tissues, and plays a critical role in wound ...
to
myofibroblast
A myofibroblast is a cell phenotype that was first described as being in a state between a fibroblast and a smooth muscle cell.
Structure
Myofibroblasts are contractile web-like fusiform cells that are identifiable by their expression of α-sm ...
differentiation.
Aberrant persistence of
myofibroblast
A myofibroblast is a cell phenotype that was first described as being in a state between a fibroblast and a smooth muscle cell.
Structure
Myofibroblasts are contractile web-like fusiform cells that are identifiable by their expression of α-sm ...
s within tissues can lead to progressive tissue
fibrosis
Fibrosis, also known as fibrotic scarring, is a pathological wound healing in which connective tissue replaces normal parenchymal tissue to the extent that it goes unchecked, leading to considerable tissue remodelling and the formation of perma ...
, impairing tissue or organ function (e.g. skin
hypertrophic
Hypertrophy is the increase in the volume of an organ or tissue due to the enlargement of its component cells. It is distinguished from hyperplasia, in which the cells remain approximately the same size but increase in number.Updated by Linda J ...
or
keloid
Keloid, also known as keloid disorder and keloidal scar,
is the formation of a type of scar which, depending on its maturity, is composed mainly of either type III (early) or type I (late) collagen. It is a result of an overgrowth of granulation t ...
scars,
liver cirrhosis
Cirrhosis, also known as liver cirrhosis or hepatic cirrhosis, and end-stage liver disease, is the impaired liver function caused by the formation of scar tissue known as fibrosis due to damage caused by liver disease. Damage causes tissue repai ...
,
myocardial fibrosis
Cardiac fibrosis commonly refers to the excess deposition of extracellular matrix in the cardiac muscle, but the term may also refer to an abnormal thickening of the heart valves due to inappropriate proliferation of cardiac fibroblasts. Fibrotic c ...
,
chronic kidney disease
Chronic kidney disease (CKD) is a type of kidney disease in which a gradual loss of kidney function occurs over a period of months to years. Initially generally no symptoms are seen, but later symptoms may include leg swelling, feeling tired, vo ...
).
Medical applications
Drug target
The identification of EGFR as an
oncogene
An oncogene is a gene that has the potential to cause cancer. In tumor cells, these genes are often mutated, or expressed at high levels. has led to the development of anticancer therapeutics directed against EGFR (called "EGFR inhibitors", EGFRi), including
gefitinib
Gefitinib, sold under the brand name Iressa, is a medication used for certain breast, lung and other cancers. Gefitinib is an EGFR inhibitor, like erlotinib, which interrupts signaling through the epidermal growth factor receptor (EGFR) in targe ...
,
erlotinib
Erlotinib, sold under the brand name Tarceva among others, is a medication used to treat non-small cell lung cancer (NSCLC) and pancreatic cancer. Specifically it is used for NSCLC with mutations in the epidermal growth factor receptor (EGFR) â ...
,
afatinib
Afatinib, sold under the brand name Gilotrif among others, is a medication used to treat non-small cell lung carcinoma (NSCLC). It belongs to the tyrosine kinase inhibitor family of medications. It is taken by mouth.
It is mainly used to treat ...
,
brigatinib
Brigatinib, sold under the brand name Alunbrig among others, is a small-molecule targeted cancer therapy being developed by Ariad Pharmaceuticals, Inc. Brigatinib acts as both an anaplastic lymphoma kinase (ALK) and epidermal growth factor re ...
and
icotinib
Icotinib (trade name Conmana) is a highly selective, first generation epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI). Icotinib is approved for use in China as first-line monotherapy in patients with non-small-cell lung can ...
for lung cancer, and
cetuximab
Cetuximab, sold under the brand name Erbitux, is an epidermal growth factor receptor (EGFR) inhibitor medication used for the treatment of metastatic colorectal cancer and head and neck cancer. Cetuximab is a chimeric (mouse/human) monoclonal an ...
for
colon cancer
Colorectal cancer (CRC), also known as bowel cancer, colon cancer, or rectal cancer, is the development of cancer from the colon or rectum (parts of the large intestine). Signs and symptoms may include blood in the stool, a change in bowel mo ...
. More recently AstraZeneca has developed
Osimertinib
Osimertinib, sold under the brand name Tagrisso, is a medication used to treat non-small-cell lung carcinomas with specific mutations. It is a third-generation epidermal growth factor receptor tyrosine kinase inhibitor.
The most common side eff ...
, a third generation tyrosine kinase inhibitor.
Many therapeutic approaches are aimed at the EGFR. Cetuximab and
panitumumab
Panitumumab, sold under the brand name Vectibix, is a fully human monoclonal antibody specific to the epidermal growth factor receptor (also known as ''EGF receptor'', ''EGFR'', ''ErbB-1'' and ''HER1'' in humans).
Panitumumab is manufactured by ...
are examples of
monoclonal antibody
A monoclonal antibody (mAb, more rarely called moAb) is an antibody produced from a cell Lineage made by cloning a unique white blood cell. All subsequent antibodies derived this way trace back to a unique parent cell.
Monoclonal antibodies ca ...
inhibitors. However the former is of the
IgG1
Immunoglobulin G (Ig G) is a type of antibody. Representing approximately 75% of serum antibodies in humans, IgG is the most common type of antibody found in blood circulation. IgG molecules are created and released by plasma B cells. Each IgG a ...
type, the latter of the
IgG2
Immunoglobulin G (Ig G) is a type of antibody. Representing approximately 75% of serum antibodies in humans, IgG is the most common type of antibody found in blood circulation. IgG molecules are created and released by plasma B cells. Each IgG a ...
type; consequences on
antibody-dependent cellular cytotoxicity
Antibody-dependent cellular cytotoxicity (ADCC), also referred to as antibody-dependent cell-mediated cytotoxicity, is a mechanism of cell-mediated immune defense whereby an effector cell of the immune system actively lyses a target cell, whose ...
can be quite different.
Other monoclonals in clinical development are
zalutumumab
Zalutumumab (proposed trade name HuMax-EGFR) is a fully human IgG1 monoclonal antibody (mAb) directed towards the epidermal growth factor receptor (EGFR). It is a product developed by Genmab in Utrecht, the Netherlands. Specifically, zalutumumab ...
,
nimotuzumab
Nimotuzumab (h-R3, BIOMAb EGFR, Biocon, India; TheraCIM, CIMYM Biosciences, Canada; Theraloc, Oncoscience, Europe, CIMAher, Center of Molecular Immunology, Havana, Cuba) is a humanized monoclonal antibody that as of 2014 had orphan status in the ...
, and
matuzumab. The monoclonal antibodies block the extracellular ligand binding domain. With the binding site blocked, signal molecules can no longer attach there and activate the tyrosine kinase.
Another method is using small molecules to inhibit the EGFR tyrosine kinase, which is on the cytoplasmic side of the receptor. Without kinase activity, EGFR is unable to activate itself, which is a prerequisite for binding of downstream adaptor proteins. Ostensibly by halting the signaling cascade in cells that rely on this pathway for growth, tumor proliferation and migration is diminished.
Gefitinib
Gefitinib, sold under the brand name Iressa, is a medication used for certain breast, lung and other cancers. Gefitinib is an EGFR inhibitor, like erlotinib, which interrupts signaling through the epidermal growth factor receptor (EGFR) in targe ...
,
erlotinib
Erlotinib, sold under the brand name Tarceva among others, is a medication used to treat non-small cell lung cancer (NSCLC) and pancreatic cancer. Specifically it is used for NSCLC with mutations in the epidermal growth factor receptor (EGFR) â ...
,
brigatinib
Brigatinib, sold under the brand name Alunbrig among others, is a small-molecule targeted cancer therapy being developed by Ariad Pharmaceuticals, Inc. Brigatinib acts as both an anaplastic lymphoma kinase (ALK) and epidermal growth factor re ...
and
lapatinib
Lapatinib (INN), used in the form of lapatinib ditosylate (USAN) (trade names Tykerb and Tyverb marketed by Novartis) is an orally active drug for breast cancer and other solid tumours. It is a dual tyrosine kinase inhibitor which interrupts t ...
(mixed EGFR and ERBB2 inhibitor) are examples of small molecule
kinase
In biochemistry, a kinase () is an enzyme that catalyzes the transfer of phosphate groups from high-energy, phosphate-donating molecules to specific substrates. This process is known as phosphorylation, where the high-energy ATP molecule don ...
inhibitors.
CimaVax-EGF, an active
vaccine
A vaccine is a biological Dosage form, preparation that provides active acquired immunity to a particular infectious disease, infectious or cancer, malignant disease. The safety and effectiveness of vaccines has been widely studied and verifie ...
targeting EGF as the major
ligand
In coordination chemistry, a ligand is an ion or molecule (functional group) that binds to a central metal atom to form a coordination complex. The bonding with the metal generally involves formal donation of one or more of the ligand's electr ...
of EGF, uses a different approach, raising
antibodies
An antibody (Ab), also known as an immunoglobulin (Ig), is a large, Y-shaped protein used by the immune system to identify and neutralize foreign objects such as pathogenic bacteria and viruses. The antibody recognizes a unique molecule of the ...
against EGF itself, thereby denying EGFR-dependent cancers of a proliferative stimulus;
it is in use as a cancer therapy against
non-small-cell lung carcinoma
Non-small-cell lung cancer (NSCLC) is any type of epithelial lung cancer other than small-cell lung carcinoma (SCLC). NSCLC accounts for about 85% of all lung cancers. As a class, NSCLCs are relatively insensitive to chemotherapy, compared to sm ...
(the most common form of lung cancer) in Cuba, and is undergoing further trials for possible licensing in Japan, Europe, and the United States.
There are several quantitative methods available that use protein phosphorylation detection to identify EGFR family inhibitors.
New drugs such as
osimertinib
Osimertinib, sold under the brand name Tagrisso, is a medication used to treat non-small-cell lung carcinomas with specific mutations. It is a third-generation epidermal growth factor receptor tyrosine kinase inhibitor.
The most common side eff ...
,
gefitinib
Gefitinib, sold under the brand name Iressa, is a medication used for certain breast, lung and other cancers. Gefitinib is an EGFR inhibitor, like erlotinib, which interrupts signaling through the epidermal growth factor receptor (EGFR) in targe ...
,
erlotinib
Erlotinib, sold under the brand name Tarceva among others, is a medication used to treat non-small cell lung cancer (NSCLC) and pancreatic cancer. Specifically it is used for NSCLC with mutations in the epidermal growth factor receptor (EGFR) â ...
and
brigatinib
Brigatinib, sold under the brand name Alunbrig among others, is a small-molecule targeted cancer therapy being developed by Ariad Pharmaceuticals, Inc. Brigatinib acts as both an anaplastic lymphoma kinase (ALK) and epidermal growth factor re ...
directly target the EGFR. Patients have been divided into EGFR-positive and EGFR-negative, based upon whether a tissue test shows a mutation. EGFR-positive patients have shown a 60% response rate, which exceeds the response rate for conventional chemotherapy.
However, many patients develop resistance. Two primary sources of resistance are the T790M Mutation and MET oncogene.
However, as of 2010 there was no consensus of an accepted approach to combat resistance nor FDA approval of a specific combination. Clinical trial phase II results reported for
brigatinib
Brigatinib, sold under the brand name Alunbrig among others, is a small-molecule targeted cancer therapy being developed by Ariad Pharmaceuticals, Inc. Brigatinib acts as both an anaplastic lymphoma kinase (ALK) and epidermal growth factor re ...
targeting the T790M mutation, and brigatinib received Breakthrough Therapy designation status by FDA in Feb. 2015.
The most common
adverse effect
An adverse effect is an undesired harmful effect resulting from a medication or other intervention, such as surgery. An adverse effect may be termed a "side effect", when judged to be secondary to a main or therapeutic effect. The term complica ...
of EGFR inhibitors, found in more than 90% of patients, is a
papulopustular A papulopustular condition is a condition composed of both papule and pustules.thefreedictionary.com > papulopustularciting:
*The American Heritage® Medical Dictionary Copyright © 2007
*Mosby's Medical Dictionary, 8th edition. © 2009
* Miller-Kea ...
rash that spreads across the face and torso; the rash's presence is correlated with the drug's antitumor effect.
In 10% to 15% of patients the effects can be serious and require treatment.
Some tests are aiming at predicting benefit from EGFR treatment, as
Veristrat.
Laboratory research using genetically engineered stem cells to target EGFR in mice was reported in 2014 to show promise. EGFR is a well-established target for monoclonal antibodies and specific tyrosine kinase inhibitors.
Target for imaging agents
Imaging agents have been developed which identify EGFR-dependent cancers using labeled EGF. The feasibility of in vivo imaging of EGFR expression has been demonstrated in several studies.
It has been proposed that certain computed tomography findings such as ground-glass opacities, air bronchogram, spiculated margins, vascular convergence, and pleural retraction can predict the presence of EGFR mutation in patients with non-small cell lung cancer.
Interactions
Epidermal growth factor receptor has been shown to
interact
Advocates for Informed Choice, dba interACT or interACT Advocates for Intersex Youth, is a 501(c)(3) nonprofit organization using innovative strategies to advocate for the legal and human rights of children with intersex traits. The organizati ...
with:
*
AR,
*
ARF4
ADP-ribosylation factor 4 is a protein that in humans is encoded by the ''ARF4'' gene.
Function
ADP-ribosylation factor 4 (ARF4) is a member of the human ARF gene family. These genes encode small guanine nucleotide-binding proteins that stimul ...
,
*
CAV1,
*
CAV3,
[
* CBL,]
* CBLB,[
* ]CBLC
Signal transduction protein CBL-C is a protein that in humans is encoded by the ''CBLC'' gene.
CBL proteins, such as CBLC, are phosphorylated upon activation of a variety of receptors that signal via protein tyrosine kinases. Through interactions ...
,
* CD44
The CD44 antigen is a cell-surface glycoprotein involved in cell–cell interactions, cell adhesion and migration. In humans, the CD44 antigen is encoded by the ''CD44'' gene on chromosome 11. CD44 has been referred to as HCAM (homing cell adhesi ...
,
* CDC25A
M-phase inducer phosphatase 1 also known as dual specificity phosphatase Cdc25A is a protein that in humans is encoded by the cell division cycle 25 homolog A (CDC25A) gene.
Function
CDC25A is a member of the CDC25 family of dual-specificity p ...
,
* CRK
Adapter molecule crk also known as proto-oncogene c-Crk is a protein that in humans is encoded by the ''CRK'' gene.
The CRK protein participates in the Reelin signaling cascade downstream of DAB1.
Function
Adapter molecule crk is a member of ...
,
* CTNNB1
Catenin beta-1, also known as beta-catenin (β-catenin), is a protein that in humans is encoded by the ''CTNNB1'' gene.
Beta-catenin is a dual function protein, involved in regulation and coordination of cell–cell adhesion and gene transcripti ...
,
* DCN,
* EGF,
* GRB14
Growth factor receptor-bound protein 14 is a protein that in humans is encoded by the ''GRB14'' gene.
The product of this gene belongs to a small family of adapter proteins that are known to interact with a number of receptor tyrosine kinases and ...
,
* Grb2,
* JAK2
Janus kinase 2 (commonly called JAK2) is a non-receptor tyrosine kinase. It is a member of the Janus kinase family and has been implicated in signaling by members of the type II cytokine receptor family (e.g. interferon receptors), the GM-CSF rec ...
,
* MUC1
Mucin short variant S1, also called polymorphic epithelial mucin (PEM) or epithelial membrane antigen (EMA), is a mucin encoded by the ''MUC1'' gene in humans. Mucin short variant S1 is a glycoprotein with extensive O-linked glycosylation of its e ...
,
* NCK1
Cytoplasmic protein NCK1 is a protein that in humans is encoded by the ''NCK1'' gene.
Gene
The Nck (non-catalytic region of tyrosine kinase adaptor protein 1) belongs to the adaptor family of proteins. The nck gene was initially isolated from ...
,
* NCK2
Cytoplasmic protein NCK2 (also known as NCK-beta and Grb4) is a protein that in humans is encoded by the ''NCK2'' gene.
Function
NCK belongs to family of adaptor proteins. There are two mammalian NCK genes, NCK1 and NCK2. NCK1 is located in ch ...
* PKC alpha
Protein kinase C alpha (PKCα) is an enzyme that in humans is encoded by the ''PRKCA'' gene.
Function
Protein kinase C (PKC) is a family of serine- and threonine-specific protein kinases that can be activated by calcium and the second messen ...
,
* PLCG1
Phospholipase C, gamma 1, also known as PLCG1,is a protein that in humans involved in cell growth, migration, apoptosis, and proliferation. It is encoded by the ''PLCG1'' gene and is part of the PLC superfamily.
Function
PLCγ1 is a cell grow ...
,
* PLSCR1
Phospholipid scramblase 1 (PL scramblase 1) is an enzyme that in humans is encoded by the ''PLSCR1'' gene.
Interactions
PLSCR1 has been shown to interact with:
* CPSF6,
* Epidermal growth factor receptor,
* NEU4,
* SHC1,
* SLPI, and
* TF ...
,
* PTPN1
Tyrosine-protein phosphatase non-receptor type 1 also known as protein-tyrosine phosphatase 1B (PTP1B) is an enzyme that is the founding member of the protein tyrosine phosphatase (PTP) family. In humans it is encoded by the ''PTPN1'' gene. PTP1B i ...
,
* PTPN11
Tyrosine-protein phosphatase non-receptor type 11 (PTPN11) also known as protein-tyrosine phosphatase 1D (PTP-1D), Src homology region 2 domain-containing phosphatase-2 (SHP-2), or protein-tyrosine phosphatase 2C (PTP-2C) is an enzyme that in huma ...
,
* PTPN6
Tyrosine-protein phosphatase non-receptor type 6, also known as Src homology region 2 domain-containing phosphatase-1 (SHP-1), is an enzyme that in humans is encoded by the ''PTPN6'' gene.
Function
The protein encoded by this gene is a member ...
,
*PTPRK
Receptor-type tyrosine-protein phosphatase kappa is an enzyme that in humans is encoded by the ''PTPRK'' gene. PTPRK is also known as PTPkappa and PTPκ.
Function
The protein encoded by this gene is a member of the protein tyrosine phosphatase ( ...
,
* SH2D3A
SH2 domain-containing protein 3A is a protein that in humans is encoded by the ''SH2D3A'' gene. The protein may be useful in Western Blots and ELISAs.
Interactions
SH2D3A has been shown to interact with the epidermal growth factor receptor
...
,
* SH3KBP1
SH3 domain-containing kinase-binding protein 1 (synonyms - CIN85, in rodents - Ruk) is an adaptor protein that in humans is encoded by the ''SH3KBP1'' gene.
Function
CBL (MIM 165360) constitutively interacts with SH3 domain-containing protein ...
,
* SHC1
SHC-transforming protein 1 is a protein that in humans is encoded by the ''SHC1'' gene. SHC has been found to be important in the regulation of apoptosis and drug resistance in mammalian cells.
SCOP classifies the 3D structure as belonging to th ...
,
* SOS1
Son of sevenless homolog 1 is a protein that in humans is encoded by the ''SOS1'' gene.
Function
SOS1 is a guanine nucleotide exchange factor (GEF) which interacts with RAS proteins to phosphorylate GDP into GTP, or from an inactive state to an ...
,
* Src,
* STAT1
Signal transducer and activator of transcription 1 (STAT1) is a transcription factor which in humans is encoded by the ''STAT1'' gene. It is a member of the STAT protein family.
Function
All STAT molecules are phosphorylated by receptor associa ...
,
* STAT3
Signal transducer and activator of transcription 3 (STAT3) is a transcription factor which in humans is encoded by the ''STAT3'' gene. It is a member of the STAT protein family.
Function
STAT3 is a member of the STAT protein family. In respons ...
,
* STAT5A
Signal transducer and activator of transcription 5A is a protein that in humans is encoded by the ''STAT5A'' gene. ''STAT5A'' orthologs have been identified in several placentals for which complete genome data are available.
Structure
STAT5a sh ...
,[
* ]UBC
The University of British Columbia (UBC) is a public research university with campuses near Vancouver and in Kelowna, British Columbia. Established in 1908, it is British Columbia's oldest university. The university ranks among the top three ...
, and
* WAS
Was or WAS may refer to:
* ''Was'', a past-tense form of the English copular verb ''to be''
People
* David Was (born c. 1952), the stage name of multi-instrumentalist and songwriter David Weiss
* Don Was (born 1952), the stage name of bass guita ...
,
* PAR2.
In fruitflies, the epidermal growth factor receptor
The epidermal growth factor receptor (EGFR; ErbB-1; HER1 in humans) is a transmembrane protein that is a receptor for members of the epidermal growth factor family (EGF family) of extracellular protein ligands.
The epidermal growth factor recept ...
interacts with Spitz
Spitz (derived from the German word ''spitz'' 'pointed') is a type of domestic dog characterized by long, thick, and often white fur, and pointed ears and muzzles. The tail often curls over the dog's back or droops. While all of the breeds rese ...
.
References
Further reading
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External links
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{{DEFAULTSORT:Epidermal Growth Factor Receptor
Tyrosine kinase receptors
Oncogenes