Showing posts with label glioma. Show all posts
Showing posts with label glioma. Show all posts

Friday, November 22, 2013

The Hedgehog, Ptch1, AND the Gli zinc-finger transcription factors

If there is an example where GENE INTERFERENCE could have a meaningful impact, it is in this pathway like a deluge of gene activations.  The impact could extend from Basal cell to bladder cancers to Gliomas!

"PTCH1 is a member of the patched gene family and is the receptor for sonic hedgehog, a secreted molecule implicated in the formation of embryonic structures and in tumorigenesis. This gene functions as a tumor suppressor. The PTCH1 gene product, is a transmembrane protein that suppresses the release of another protein called smoothened, and when sonic hedgheog binds PTCH1, smoothened is released and signals cell proliferation." wikipedia.

POLIZIO ET AL
 The vertebrate Hedgehog (Hh) pathway has essential functions during development and tissue homeostasis in normal physiology, and its dysregulation is a common theme in cancer. The Hh ligands (Sonic Hh, Indian Hh, and Desert Hh) bind to the receptors Patched1 and Patched2, resulting in inhibition of their repressive effect on Smoothened (Smo). Smo is a seven-transmembrane protein, which was only recently shown to function as a G protein–coupled receptor (GPCR) with specificity toward the heterotrimeric guanine nucleotide-binding protein Gi. In addition to activating Gi, Smo signals through its C-terminal tail to inhibit Suppressor of Fused, resulting in stabilization and activation of the Gli family of transcription factors, which execute a transcriptional response to so-called "canonical Hh signaling."

WHEN YOU TALK ABOUT ZINC-FINGER YOU KNOW YOU ARE TALKING ABOUT HISTONE MODULATION AND DIRECT DNA INTERACTION, ALL OCCURING MOSTLY THE EPIGENETIC ZONE MOSTLY!  THEREFORE THIS COULD EFFECT EVEN THE LEUKEMIAS!
THE CRBCM IS TAKING A CLOSER LOOK!

"Gli regulation by the opposing activities of Fused and Suppressor of Fused

Maximilien Murone1,2ET AL!
Hedgehog (Hh) proteins are secreted factors that control cell proliferation and cell-fate specification1. Hh signalling is mediated in vertebrates by the Gli zinc-finger transcription factors (Gli1, Gli2 and Gli3) and in Drosophila by the Gli homologue Cubitus interruptus"

OTHER GENES IMPLICATED!

PTCH1 gene
WNT3A
IRF6
GLI
TGF-beta
TrkC: Neurotropin -Receptor

AND THE DANCE OF GENES CONTINUE!

Tuesday, April 2, 2013

Secondary Hematologic Malignancies

Japanese researchers suggested in a retrospective study of patients treated with Temodar for Glioma, that there is an increased occurrence of secondary Myelodysplasia, leukemias and particularly Acute Lymphoblastic Leukemia.  It is interesting to look further, beyond the simple observation and speculate as to what leads to such a transformation at the gene level.
Leukemias are a disease not only of pathways, but of deep derangement at the Histone-DNA level and include particularly not only protein complexes similar to core binding factors, but also regulator genes which appear to be specifically amplified in leukemias!
It is pertinent to also look closer at Proteins Kinases affecting or interacting with DNA.  Temodar is an Alkylating agent per the researcher's report.
The interval between the treatment and the occurrence is also interesting, and suggests that the secondary Leukemia results from a secondary amplification of proliferative genes after the onslaught on cellular receptors by the chemical stimulus. The NK-kB, c-JUN must be in play.  Blocking these pathways could prevent such malignant occurrence. We will soon find that secondary malignancy could be prevented by simply blocking some tumor growth factors.  We don't need to accept these complications any more.  I learned that my first patient who was diagnosed with Hodgkin disease, a curable disease, died later on with an Acute Leukemia.  She was free of Hodgkin disease. Our current follow-up is inadequate in this regard, as we sit and wait for secondary leukemia to set in.  Lets look into blocking Tumor growth factors to stop secondary leukemias!