Showing posts with label ERBB2. Show all posts
Showing posts with label ERBB2. Show all posts

Sunday, April 28, 2013

MASTERING OF SOME GENES CONTROLLING RECEPTOR FUNCTIONS!

1.SLIT 2    Slit homolog 2 protein is a protein that in humans is encoded by the SLIT2 gene
                SLIT2 has been shown to interact with Glypican 1
 Cell surface heparan sulfate proteoglycans are composed of a membrane-associated protein core substituted with a variable number of heparan sulfate chains. Members of the glypican-related integral membrane proteoglycan family (GRIPS) contain a core protein anchored to the cytoplasmic membrane via a glycosyl phosphatidylinositol linkage. These proteins may play a role in the control of cell division and growth regulation.[2]  WIKIPEDIA

IF YOU RECALL OUR DISCUSSION  ABOUT RECEPTOR FAILURE, TUMOR GROWTH FACTOR FAILED TO STIMULATE OUR RECEPTOR BECAUSE OF LACK OF DERENGEMENT OF GLYCOSYLATION AND HEPARAN WAS THE FAILURE.  THIS PUT SLIT 2 AT THE RECEPTOR PARTICULARLY IN THE CENTRAL NERVOUS SYSTEM!
                              
2.MIG6:   The cytoplasmic protein MIG6 (mitogen-induced gene 6; also known as ERRFI1) interacts with and inhibits the kinase domains of EGFR and ERBB2 (refs 3–5). Crystal structures of complexes between the EGFR kinase domain and a fragment of MIG6 show that a approx25-residue epitope (segment 1) from MIG6 binds to the distal surface of the C lobe of the kinase domain. Biochemical and cell-based analyses confirm that this interaction contributes to EGFR inhibition by blocking the formation of the activating dimer interface.(ZANG ET AL!)
 MIG-6 Negative regulator of EGFR signaling in skin morphogenesis. Acts as a negative regulator for several EGFR family members, including ERBB2, ERBB3 and ERBB4. Inhibits EGFR catalytic activity by interfering with its dimerization. Inhibits autophosphorylation of EGFR, ERBB2 and ERBB4. Important for normal keratinocyte proliferation and differentiation. Plays a role in modulating the response to steroid hormones in the uterus. Required for normal response to progesterone in the uterus and for fertility. Mediates epithelial estrogen responses in the uterus by regulating ESR1 levels and activation. Important for regulation of endometrium cell proliferation. Important for normal prenatal and perinatal lung development. Interacts with ERBB2. Interacts with EGFR. Levels are very low in quiescent cells. Up-regulated by mitogens. Belongs to the MIG6 family. Note: This description may include information from UniProtKB.

3.  SATB1  HERE BECAUSE OF THE CONNECTION WITH NUCLEAR MATERIAL.  interferon gamma act through here!

4.  SMAD6
Another powerful decoy
" Smad6 specifically competes with Smad4 for binding to receptor-activated Smad1, yielding an apparently inactive Smad1-Smad6 complex. Therefore, Smad6 selectively antagonizes BMP-activated Smad1 by acting as a Smad4 decoy."  Hata et al
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LTB4, because of its interactions with

Peroxisome proliferator-activated receptor gamma has been shown to interact with:

Clinical relevance

PPAR-gamma has been implicated in the pathology of numerous diseases including obesity, diabetes, atherosclerosis, and cancer. PPAR-gamma agonists have been used in the treatment of hyperlipidaemia and hyperglycemia.[18] PPAR-gamma decreases the inflammatory response of many cardiovascular cells, particularly endothelial cells.[19] PPAR-gamma activates the PON1 gene, increasing synthesis and release of paraoxonase 1 from the liver, reducing atherosclerosis.[20]
Many insulin sensitizing drugs (namely, the thiazolidinediones) used in the treatment of diabetes target PPARG as a means to lower serum glucose without increasing pancreatic insulin secretion.
A fusion protein of PPAR-γ1 and the thyroid transcription factor PAX8 is present in approximately one-third of follicular thyroid carcinomas, to be specific those cancers with a chromosomal translocation of t(2;3)(q13;p25), which permits juxtaposition of portions of both genes.[21] [22]
Recently pioglitazone, a PPAR-γ agonist has been shown to be effective in reducing inflammation in Parkinson's Disease models. Levels of MMPs and microglia (and therefore TNF-α and other cytokine levels) were found to be reduced. Thus it has been shown to be neuroprotective in MPTP mouse models.

BMP2
The protein encoded by this gene belongs to the transforming growth factor-beta (TGFB) superfamily. The encoded protein acts as a disulfide-linked homodimer and induces bone and cartilage formation. [provided by RefSeq, Jul 2008]

Saturday, March 16, 2013

PROOF OF CONCEPTS: THE CASE OF PANCREATIC CANCER

1.  "P" ARM VERSUS  "Q"
-----------------------------
As you look at the location of Genes, one will quickly notice that various genes have their family counterpart not close on the same chromosome. But instead on a different chromosome altogether.  In general we almost treat this  information in a profane manner in that we overlook the meaning of this.  Nature, however, has no place for randomness. Everything has deep meaning and NUANCES OR MINIMAL VARIATIONS can make a world of difference. Should you doubt this statement, ask the people with Sickle cell, they are not laughing about that nuance in Hemoglobins.  So when a family member has put in a different chromosome, there is no pun intended.

ERBB1 is on chromosome 7p12 (involved in Glioblastoma and Squamous cell head and neck cancers)
ERBB2 is on chromosome 17q11.2-q12 (involved in breast, Ovarian and cervical cancer)

Also however, we note that the family member is put on a "p" rather than "q" location.  This also has a profound meaning.   It just turn out that mutation on "q" location seems to have the worse prognosis and are more likely to be expressed  than those on "p" location.

The bad guy MYC is located 8q24 and is found on advanced forms of cancers (Ovarian, Breast, small cell, Esophageal and cervical but also in the Burkitt (ALL))
The nice MYCN, often a better prognosis indicator, is located on 2p24  but still can be involved in Neurobalstoma.

These are in fact speculation but check it out!

Another example
just go ahead and compare
breast cancer with FGFR1 located 8p11
and breast cancer with EGFR1 located 10q25
and call me if you find different!

PROOF OF CONCEPT NEEDED FOR PANCREATIC CANCER:

One of the complication or hurdle you encounter when you are dealing with abnormal genes
in pancreatic cancers is the the genes found in abnormal cancers are also found in benign conditions such as Adenoma or even pancreatitis.  Now if we assume that this is an Adenocarcinoma of the same origin embryonically as the colon (check that assumption out), we could apply the colon cancer model where
EARLY CANCER FOR ADENOCARCINOMA IS ANNOUNCED BY LOSS OR MUTATION IN CHROMOSOME 17:   IE GENES     (FOLLOWING THE COLON MODEL)
-----------------------------------
-KRT20
-TEM 7
-MAP2K4
BAT-26
ALOX 12
TP53
BIRC5
NME1
ERBB2
GAS
TM4SF5

LATE CANCER,  LOSS OF CHROMOSOME 8 (FOLLOWING THE COLON MODEL)

CDH4
PSCA
MYC
 (FGFR1 AND BAG4 ARE HAVE A "p" LOCATION ON THE CHROMOSOSME)