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Showing posts with label Mebendazole. Show all posts
Showing posts with label Mebendazole. Show all posts

Wednesday 30 November 2022

Repurposing Anti-parasite drugs to treat Cancer and Autism?

 

I should start this post by highlighting that generally cancer and autism are not caused by parasites.

I have to be a little careful because we now know that certain types of virus and bacteria are involved in the initial trigger to initiate some types of cancer. This is why many females are now offered human papillomavirus (HPV) vaccines to minimize the chance of several different cancers. I noticed recently that in the US this vaccine is advertised on TV.  I used to know a woman who like most people had the HPV virus as a child, but did not have this vaccine.  She developed a rare oral cancer that the vaccine would have protected against and died very young. We saw in a previous post how a specific gut bacteria blocks the initiation of childhood leukemia.

The pharmaceutical industry does not seem to like the idea of repurposing existing drugs to treat a different disease.  There are some exceptions; it is OK to treat females with acne, using the diuretic drug Spironolactone.  Nobody seems to object to the treatment of intractable headaches with drugs actually approved to lower blood pressure (Verapamil, Amlodipine etc).

When investigating cancers you have to look at the specific underlying mechanisms, just as you do with autism.

As we saw long ago in this blog, it has been suggested to classify autism as either over-active pro-growth signaling pathways, or under-active pro-growth signaling pathways. Most is the over-active type.

Cancer is very clearly another example of over-active pro-growth signaling pathways, so it is not surprising that there is an overlap between therapies for autism and cancer.  The difference is that they are far more likely to be effective in autism. 

So, a cheap anti-parasite drug for kids like Mebendazole, which just happens to also be a Wnt inhibitor,  may slow down the growth of some cancers, but it is sadly not curative.  In an autistic brain where Wnt signalling might be overactive, a lower dose of Mebendazole, might well provide a long-term benefit.   

My old posts that mention Wnt signaling are here:-

https://www.epiphanyasd.com/search/label/Wnt 

Wnt signaling interestingly plays a role in how your hair will go gray/grey. If you reduce Wnt signaling, your hair will go gray and so this is an inevitable side effect of a potent Wnt inhibitor. 

Premature graying might indeed indicate reduced Wnt activity.

 

Pyrantel pamoate

Our reader Dragos recently fined tuned his adult son’s anti-aggression therapy and he recently shared his latest innovation:-

 

"you have to give him 20mg of propranolol 2-3 times a day, pyrantel pamoate 750mg in the evening for 2-3 days, and you will see that his anger will disappear, stay on propranolol. After 3 weeks repeat with antiparasitic, you will see that I was right, you don't use psychotropic drugs"

 

Propranolol is a normally used to lower blood pressure, but it does this in a way that also reduces anxiety.  At the low doses used by Dragos, it has been used to treat actors with stage fright. It can be used before exams or driving tests, to calm the person down.

Propranolol has been trialed in autism. Some people use a low dose and some use a higher dose.

Pyrantel pamoate is used to treat hookworms and other parasites that can be picked up by young children. It works by paralyzing the worms. This is achieved by blocking certain acetylcholine receptors in the worm.

As is very often the case, pyrantel pamoate likely has other modes of action that are entirely different. Is it a Wnt inhibitor like the other hookworm treatment Mebendazole?

I did a  quick search on google and it gave me the wrong pamoate. 

Pyrvinium pamoate is able to kill various cancer cells, especially CSC. The drug functions through the reduction of WNT- and Hedgehog-dependent signaling pathways (Dattilo et al., 2020). 

Pyrvinium pamoate is yet another anti-parasitic drug, but not the one Dragos is using.

So pyrantel pamoate may not be a Wnt inhibitor, unlike many anthelmintic drugs, but it is used by the “anti-parasitic re-purposer in chief” Dr Simon Wu.  He publishes his findings/thoughts, which is good to see.  He likes to combine different anti-parasitic drugs.

I did look up the effect of pyrantel pamoate on gene expression.  There is data, but you really need to see the source material to know whether anything is valid.

Inhibiting GSTP1 (glutathione S-transferase pi 1) is suggested and that is a feature in common with an anti-parasite drug class called Thiazolides (e.g.  Nitazoxanide).  That would make pyrantel pamoate a potential therapy for triple-negative breast cancer, where the cancer cells rely on vigorous activity by the enzyme glutathione-S-transferase Pi1 (GSTP1).  Cancer cells are highly vulnerable to oxidative stress, and as we know glutathione is the main way the body extinguishes it. Glutathione S-transferases P1 protects breast cancer cell from cell death.  So you want to inhibit GSTP1.

Pyrantel has many other suggested effects even reducing expression of the gene FXR2 (fragile X mental retardation,2) and increasing expression of the gene MTSS1 (metastasis suppressor 1).

Pyrantel is even suggested as an epilepsy drug.

 

Drug repositioning in epilepsy reveals novel antiseizure candidates

Epilepsy treatment falls short in ~30% of cases. A better understanding of epilepsy pathophysiology can guide rational drug development in this difficult to treat condition. We tested a low-cost, drug-repositioning strategy to identify candidate epilepsy drugs that are already FDA-approved and might be immediately tested in epilepsy patients who require new therapies.

Expanding on these analyses of epilepsy gene expression signatures, this study generated a list of 184 candidate anti-epilepsy compounds. This list of possible seizure suppressing compounds includes 129 drugs that have been previously studied in some model of seizures and 55 that have never been studied in the context of seizures. 91 of these 184 compounds are already FDA approved for human use, but not for treating seizures or epilepsy. We selected four of these drugs (doxycycline, metformin, nifedipine, and pyrantel tartrate) to test for seizure suppression in vivo.

Pyrantel tartrate is an antiparasitic agent that acts by inhibiting fumarate reductase, and by directly acting on acetylcholine receptors at the neuromuscular junction of infecting helminths. Pyrantel tartrate is FDA approved for use in domestic animals and has been used to treat human parasitic infections.73 Unlike nifedipine and metformin (for which some rodent studies and human reports relate to seizures), a March 2018 PubMed search for “pyrantel and epilepsy” and “pyrantel and seizure” found no manuscripts that studied pyrantel in seizures. Thus, pyrantel tartrate represents a truly novel antiseizure drug candidate yielded by our screen.

 

All in all it is not surprising that Dr Yu is prescribing pyrantel pamoate.

Digging any deeper is beyond the scope of a blog post.

What is clear is that pyrantel pamoate and mebendazole are unlikely to be equally effective in Dragos’ son.

Other anti-parasite drugs work very differently.

In the chart the mode of action of some common drugs  is presented.

 

Anthelminticsfor drug repurposing: Opportunities and challenges

 

Mode of action of albendazole (ABZ), ivermectin (IVM), levamisole (LV), mebendazole (MBZ), niclosamide (NIC), flubendazole (FLU), rafoxanide (RAF), nitazoxanide (NTZ), pyrvinium pamoate (PP), and eprinomectin (EP).

  

Suramin is now quite well known as a potential autism therapy and two different groups are trying to commercialize it.  Suramin is the original anti-purinergic drug (APD), it blocks purinergic receptors that have names like P2Y2.

When I looked at PAK1 a long time ago, which was put forward as a treatment pathway for neurofibromatosis, some schizophrenia and some autism I came across Ivermectin as an existing alternative to the research drug FRAX486, or the expensive BIO 30 propolis from New Zealand.

A decade later and the world goes crazy when the idea of using Ivermectin to treat COVID 19 gets well publicized.  The good news is that now we know that regular use of Ivermectin is not as dangerous as people thought it would be.  Many people have been using the veterinary version in the US, Brazil and elsewhere. 

The supporting research:- 

Effect of Pyrantel on gene expression.

 https://maayanlab.cloud/Harmonizome/gene_set/pyrantel-5513/CMAP+Signatures+of+Differentially+Expressed+Genes+for+Small+Molecules

 

decreases expression of:-

FXR2   fragile X mental retardation, autosomal homolog 2

(and many more)

 

Increases expression of

MTSS1 metastasis suppressor 1

BNIP1 BCL2/adenovirus E1B 19kDa interacting protein 1

BRAF B-Raf proto-oncogene, serine/threonine kinase

(and many more)

 

https://maayanlab.cloud/Harmonizome/gene_set/Pyrantel+Pamoate/CTD+Gene-Chemical+Interactions

Glutathione S-transferase P is an enzyme that in humans is encoded by the GSTP1 gene.

Pyrantel Pamoate Gene Set

Dataset          CTD Gene-Chemical Interactions

2 genes/proteins interacting with the chemical Pyrantel Pamoate from the curated CTD Gene-Chemical Interactions dataset.

GPR35    G protein-coupled receptor 35

GSTP1   glutathione S-transferase pi 1

 

Triple-negative breast cancer target is found

They discovered that cells from triple-negative breast cancer cells rely on vigorous activity by an enzyme called glutathione-S-transferase Pi1 (GSTP1). They showed that in cancer cells, GSTP1 regulates a type of metabolism called glycolysis, and that inhibition of GSTP1 impairs glycolytic metabolism in triple-negative cancer cells, starving them of energy, nutrients and signaling capability. Normal cells do not rely as much on this particular metabolic pathway to obtain usable chemical energy, but cells within many tumors heavily favor glycolysis.

  

"Inhibiting GSTP1 impairs glycolytic metabolism," Nomura said. "More broadly, this inhibition starves triple-negative breast cancer cells, preventing them from making the macromolecules they need, including the lipids they need to make membranes and the nucleic acids they need to make DNA. It also prevents these cells from making enough ATP, the molecule that is the basic energy fuel for cells." 

 

Anthelmintics for drug repurposing: Opportunities and challenges 

It has been demonstrated that some of the anthelmintics are able to inhibit critical oncogenic pathways, such as Wnt/β-catenin, signal transducer and activator of transcription proteins 3 (STAT3), and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB; therefore, their application for cancer treatment has been considered.

 

Repositioning of Anthelmintic Drugs for the Treatment of Cancers of the Digestive System

 

Anthelmintics for drug repurposing: Opportunities and challenges

 

Mode of action of albendazole (ABZ), ivermectin (IVM), levamisole (LV), mebendazole (MBZ), niclosamide (NIC), flubendazole (FLU), rafoxanide (RAF), nitazoxanide (NTZ), pyrvinium pamoate (PP), and eprinomectin (EP).

 

Thiazolides inhibit growth and induce glutathione-S-transferase Pi (GSTP1)-dependent cell death in human colon cancer cells


More research on the repurposing anti-parasite drugs: 


Antiparasitic and Antifungal Medications for Targeting Cancer Cells Literature Review and Case Studies Frederick T. Guilford, MD; Simon Yu, MD

Chronic inflammation is a new catch phrase for the explanation of all chronic degenerative diseases, from asthma, arthritis, heart disease, auto-immune disease, and irritable bowel disease to cancer. Occult infections from oncovirus, bacterial, and fungal infections as well as from lesser known parasitic infections are driving forces in the cellular evolution and degeneration of cancer cells. An approach using currently available medications that target both fungal and parasitic metabolism appears to interfere with the metabolic synergy that is associated with tumor growth and aggressiveness 

 

The Antitumor Potentials of Benzimidazole Anthelmintics as Repurposing Drugs 

 

Repurposing Drugs in Oncology (ReDO)—mebendazole as an anti-cancer agent 

 

A Pinworm Medication Is Being Tested As A Potential Anti-Cancer Drug


 Conclusion

I did suggest long ago that Mebendazole, as a Wnt inhibitor, might be a cheap and effective treatment for some autism.  I had envisaged that it would need to be given daily, as it is in the cancer trials.

Dragos’ use of pyrantel pamoate, for an average of 4 days a month is interesting.  It is cheap, safe and practical.

One key issue with antiparasitic drugs is how much is absorbed into the blood stream.  If 100% of the drug stays in the gut, its benefit will be limited.

About 20% of Mebendazole ends up in the blood stream and if you take it often this figure is reported to increase.

The combo of propranolol + pyrantel pamoate is an interesting option to treat self-injury and aggressive behavior.  It works for Dragos and undoubtedly will for some others.

Is the inhibition of Wnt signalling the reason why pyrantel pamoate is effective for Dragos’ son?  There is no evidence to support that.

Are antiparasitic drugs going to be widely adopted to treat any unrelated conditions, cancer included, I very much doubt it.

Cancer is better avoided, than treated.  It is a much more achievable objective.

The Fragile X researcher Randi Hagerman takes metformin, as her chemoprevention therapy. She is the medical director of MIND Institute at the University of California, Davis.

You can raise IQ in people with Fragile X by 10-15% using Metformin.  I guess Randi had been reading up on Metformin and came across the anti-cancer effects.

If I had to suggest an anti-parasite drug for Randi to try in Fragile X, I would suggest the PAK inhibitor Ivermectin, made (in)famous by Donald Trump and Jair Bolsonaro during Covid. The research drug FRAX 486 is called FRAX for Fragile X. It is a PAK inhibitor that never made it to market.  Ivermectin is an existing drug that is also a PAK inhibitor.  Worth a try, Randi?

I expect Dr Yu might try and increases his chances and make a combo with a second anti-parasitic drug.

Metformin is one of several anti-cancer choices, it depends which type of cancer is of concern. For RAS-dependent cancer I think Atorvastatin is the best choice. 

If you read the research, like me and Randi, chemoprevention is the obvious choice for older adults. Dementia prevention is equally obvious.

Parkinson’s prevention may be achieved by blocking Cav1.3 (amlodipine etc)

Alzheimer’s prevention may be achieved using low dose fenamates (Ponstan etc).

For vascular dementia and Alzheimer’s prevention/treatment spermidine (in the form of modified wheatgerm) is promising.

Anti-parasite drugs for cancer and autism? Yes, it sounds mad. But is it?

What is for sure is that your pediatrician will think you have gone mad!

Our reader MG in Hong Kong will have got some new ideas to think about.






Thursday 18 April 2019

Wnt, TCF4 and Pre-myelinating Oligodendrocytes


Cartoons in art class - Monty is getting ready for Easter break, but not in the Maldives

Today’s post may sound very complicated and narrow, but it is very relevant to people with the following: - 

·        Pitt Hopkins Syndrome (insufficient expression of the Transcription Factor #4  TCF4 gene)

·        Multiple Sclerosis

·        Some Mental Retardation/Intellectual Disability (MR/ID)

·        Schizophrenia

·        Impaired Wnt signalling

·        Perhaps PAK1 inhibitor responders

I do feel that Multiple Sclerosis could be treated very much better if some effort was made to translate the existing science, freely available to all, into therapy. You could greatly improve many people’s lives just by repurposing cheap existing drugs.
In simple terms, to produce myelin that you need to coat axons in your brain, you need a type of cell called an oligodendrocyte (OL).  You need a lot of these cells and you need them to get busy. They place tiny pieces of white insulation along axons of your brain cells, this produces the so called “white matter”.  These pieces of insulation are needed to make electrical signals flow correctly in your brain.
It has been shown that in some people the oligodendrocyte precursors (OLPs) do not “mature” and instead get stuck as premyelinated oligodendrocytes (pre-OL). That means reduced myelination and loss of white matter.

It is clearly shown in the graphic below: -








































Tcf4 is expressed in oligodendrocyte lineage in human developmental white matter and in active areas of MS lesions. (A) Tcf4 is expressed in white matter tracts during myelination of human developmental brain at postnatal age 1 mo, 3.5 mo, and 16 mo, but is not expressed by 7 yr. Tcf4 colocalizes with Olig2 when expressed in the developing human corpus callosum. (B) Tcf4 protein expression is evident in active MS lesions, but it is not seen in normal-appearing white matter (NAWM) or in the core of chronic MS lesions. An illustrative MS case is shown with several lesion types present. NAWM stains with Luxol Fast Blue (LFB) and contains sparse LN3(HLA-DR)-positive inflammatory cells, organized SMI-31 axon fibers, and no Tcf4-positive cells. Chronic plaques have sparse LFB staining and LN3-positive cells, intact axons, but no Tcf4-positive cells. In contrast, Tcf4-positive cells are present in active areas of plaques with abundant LN3-positive cells and intact demyelinated axons. Tcf4 expression in active lesions colocalizes (open arrowheads) with a subset of Olig2 cells.


Don’t worry if you don't follow everything. There is nothing wrong with your white matter.
We come back to Wnt signalling that we covered in depth in older posts. This is a complex signalling pathway implicated in autism, some cancers and other conditions. You can both increase and reduce Wnt signalling, which will affect the transcription of numerous genes.
TCF4 is the Pitt Hopkins gene. We have across this syndrome several times, while it is rare, a milder miss-expression of the gene is actually quite common.  Reduced expression of TCF4 is a common feature of MR/ID very broadly. TCF4 has been found to be over-expressed in schizophrenia.
People with Multiple Sclerosis (MS) have been found to have oligodendrocytes “stuck” as non-myelinating (premyelinated oligodendrocytes, pre-OL). Inhibiting the Wnt pathway might play a role in treatment during periods of acute demyelination, when there is a lack of newly minted myelin-producing oligodendrocytes. The study below does refer to Wnt inhibitors in the pipeline as potential cancer therapies.  It looks to me that safe Wnt inhibitors like the cheap drugs widely used to treat children with parasites (Mebendazole/ Niclosamide) could be repurposed to treat the acute phase of multiple sclerosis.
Mebendazole/ Niclosamide are safe and dirt cheap, whereas the (slightly) disease changing MS drugs currently cost $50,000+ a year.

TCF4 links everything together
Wnt signalling needs to be active to block premyelinated oligodendrocytes into transforming into oligodendrocytes (OL). So by inhibiting Wnt signalling you may remove one of the problems in MS; you probably only need to do this during relapses of MS.  
There actually is a finally stage to getting the oligodendrocytes (OL) to myelinate many axons and not be lazy.
In the jargon “dysregulation of Wnt–β-catenin signaling in OLPs results in profound delay of both developmental myelination and remyelination”.
A miss-expression of TCF4 is clearly also going to affect myelination and its does in both Pitt Hopkins and MS.
One feature of Pitt Hopkins (caused by haploinsufficiency of the transcription factor 4) is indeed delayed myelination measured via MRI at the age of 1. By the age of 9 white matter (the myelin-coated part of your brain) appears normal. This fits with what I highlighted in red under figure 6 above.
Nothing is simple. Activating Wnt signalling is known to increase expression of TCF4.  


The progressive loss of CNS myelin in patients with multiple sclerosis (MS) has been proposed to result from the combined effects of damage to oligodendrocytes and failure of remyelination. A common feature of demyelinated lesions is the presence of oligodendrocyte precursors (OLPs) blocked at a premyelinating stage. However, the mechanistic basis for inhibition of myelin repair is incompletely understood. To identify novel regulators of OLP differentiation, potentially dysregulated during repair, we performed a genome-wide screen of 1040 transcription factor-encoding genes expressed in remyelinating rodent lesions. We report that 50 transcription factor-encoding genes show dynamic expression during repair and that expression of the Wnt pathway mediator Tcf4 (aka Tcf7l2) within OLPs is specific to lesioned—but not normal—adult white matter. We report that β-catenin signaling is active during oligodendrocyte development and remyelination in vivo. Moreover, we observed similar regulation of Tcf4 in the developing human CNS and lesions of MS. Data mining revealed elevated levels of Wnt pathway mRNA transcripts and proteins within MS lesions, indicating activation of the pathway in this pathological context. We show that dysregulation of Wnt–β-catenin signaling in OLPs results in profound delay of both developmental myelination and remyelination, based on (1) conditional activation of β-catenin in the oligodendrocyte lineage in vivo and (2) findings from APCMin mice, which lack one functional copy of the endogenous Wnt pathway inhibitor APC. Together, our findings indicate that dysregulated Wnt–β-catenin signaling inhibits myelination/remyelination in the mammalian CNS. Evidence of Wnt pathway activity in human MS lesions suggests that its dysregulation might contribute to inefficient myelin repair in human neurological disorders 
Potential Tcf4-catenin activities in oligodendrocyte development
The pattern of Tcf4 protein expression, from P1 to P30 and during remyelination after injury, defines the window of potential canonical Wnt pathway functions. Within this context, we observed that Tcf4 expression marked 15%–20% of OLPs at any given stage assessed. These findings were consistent with two possibilities. First, Tcf4 expression could demarcate a subset of OLPs. Second, it was possible that Tcf4 expression transiently marks all (or the vast majority) of OLPs during development. Our functional evidence strongly supports the latter conclusion, based on the fact that activity of activated β-catenin is Tcf-dependent (van de Wetering et al. 2002), coupled with the robust phenotype in DA-Cat and APCMin animals, in which we observe pervasive effects of Wnt pathway dysregulation on myelin production throughout the CNS. Interestingly, although Tcf4 proteins are coexpressed with nuclear Olig1 proteins, Tcf4 segregated from cells expressing Olig1 mRNA transcripts, consistent with the possibility that Tcf4 is expressed at a transition stage when nuclear Olig1 proteins become down-regulated during remyelination.

Previous work has suggested inhibitory functions of Tcf4 on myelin basic protein gene expression in vitro (He et al. 2007), and our studies indicate that Tcf4 interactions with β-catenin inhibit myelination in vivo. Additional studies are warranted to rule out possible β-catenin-independent roles for Tcf4 in oligodendrocyte development. Although Wnt pathway activation has conventionally been thought of as activating gene targets, recent work has identified novel Tcf–β-catenin DNA regulatory binding sites that repress targets (Blauwwkamp et al. 2008). In this regard, one intriguing candidate target is HYCCIN (DRCTNNB1A), a Wnt-repressed target (Kawasoe et al. 2000) with essential roles in human myelination (Zara et al. 2006), which is expressed in rodent oligodendrocytes and down-regulated in Olig2cre/DA-Cat mice (Supplemental Fig. 8). Further studies are needed to better understand Tcf4–catenin function and its direct gene targets during oligodendrocyte lineage progression.

Wnt pathway dysregulation in OLPs as a mechanism leading to chronic demyelination in human white matter diseases
Therapeutic opportunities might arise from an enhanced understanding of the process regulating normal kinetics of remyelination. How might the negative regulatory role of the canonical Wnt pathway help to explain the pathology of demyelinating disease? Delayed remyelination due to Wnt pathway dysregulation in OLPs could lead to chronic demyelination by OLPs then missing a “critical window” for differentiation (Miller and Mi 2007; Franklin and Ffrench-Constant 2008). This “dysregulation model” of remyelination failure requires the Wnt pathway to be active during acute demyelination, as suggested by data from our animal systems and human MS tissue.
Canonical WNT signaling has been implicated in a variety of human diseases (Nelson and Nusse 2004), and gain-of-function mutations in β-catenin are etiologic in several cancers including the majority of colon adenocarcinomas. Approaches for treating Wnt-dependent cancers by promoting differentiation (and hence cell cycle arrest or apoptosis) using pharmacological inhibitors of the pathway are under development (Barker and Clevers 2005). It is possible that such antagonists might play a role in the therapeutic enhancement of remyelination by normalizing the kinetics of myelin repair. If so, the animal models described here (e.g., APC+/−) should be useful in preclinical testing. However, it is important to note that while dysregulation of a pathway might delay remyelination, it is overly simplistic to expect that inhibition of the same pathway would accelerate repair in the complex milieu of an MS lesion in which several inhibitory pathways might be active, compounded by the presence of myelin debris (Kotter et al. 2006). Indeed, because of the need to synergize with other processes (e.g., those associated with inflammation), accelerated differentiation might negatively affect repair (Franklin and Ffrench-Constant 2008). Further work is needed to comprehensively understand interactions of regulatory networks required for optimal remyelination and how these may be dysregulated in human demyelinating diseases.

Neurologic and ocular phenotype in Pitt-Hopkins syndrome and a zebrafish model.


Abstract


In this study, we performed an in-depth analysis of the neurologic and ophthalmologic phenotype in a patient with Pitt-Hopkins syndrome (PTHS), a disorder characterized by severe mental and motor retardation, carrying a uniallelic TCF4 deletion, and studied a zebrafish model. The PTHS-patient was characterized by high-resolution magnetic resonance imaging (MRI) with diffusion tensor imaging to analyze the brain structurally, spectral-domain optical coherence tomography to visualize the retinal layers, and electroretinography to evaluate retinal function. A zebrafish model was generated by knockdown of tcf4-function by injection of morpholino antisense oligos into zebrafish embryos and the morphant phenotype was characterized for expression of neural differentiation genes neurog1, ascl1b, pax6a, zic1, atoh1a, atoh2b. Data from PTHS-patient and zebrafish morphants were compared. While a cerebral MRI-scan showed markedly delayed myelination and ventriculomegaly in the 1-year-old PTHS-patient, no structural cerebral anomalies including no white matter tract alterations were detected at 9 years of age. Structural ocular examinations showed highly myopic eyes and an increase in ocular length, while retinal layers were normal. Knockdown of tcf4-function in zebrafish embryos resulted in a developmental delay or defects in terminal differentiation of brain and eyes, small eyes with a relative increase in ocular length and an enlargement of the hindbrain ventricle. In summary, tcf4-knockdown in zebrafish embryos does not seem to affect early neural patterning and regionalization of the forebrain, but may be involved in later aspects of neurogenesis and differentiation. We provide evidence for a role of TCF4/E2-2 in ocular growth control in PTHS-patients and the zebrafish model. 


Conclusion  

If you have a myelinating disease, you might want to read up on TCF4 and Wnt signalling. Probably not what the Minions take to read on the beach in the Maldives.

We also should recall the importance of what I am calling the "what, when and where" in neurological disorders. This is important for late onset disorders like schizophrenia, since the symptoms often develops in late teenage years and so it is potentially preventable, if identified early enough.

Today we see that TCF4 is expressed in white matter only in early childhood. If you knew what changes take place in the brains of children who go on to develop schizophrenia, you might well be able to prevent its onset.

Preventing some autism is already possible, as has been shown in mouse models, but in humans it is more complicated because of the "when" and quite literally the "where". There will be a post showing how the brain overgrowth typical of autism can be prevented using bumetanide, before it occurs, at least in mice.


  












Sunday 9 July 2017

More Wnt Modulation for Autism and More Inexpensive Potential Cancer Therapies


This blog is of course meant to be about autism, but today it is again more about cancer, since I keep coming across interesting potential therapies while researching Wnt/PAK/hedgehog therapies for autism.

On their way to visit a pharmacy?

It really looks like daily use of Mebendazole should be beneficial in some types of autism and perhaps a little short term bioavailability boost from cimetidine might help get things started. There are anecdotes on the internet of people with autism using it for its anti-parasite properties and showing a behavioral improvement.
Wnt signalling is highly complex and yet still only partially understood. One interesting role of Wnt signalling is in controlling the flow of calcium ions within cells. The non-canonical Wnt/calcium pathway helps to regulate calcium release from the endoplasmic reticulum (ER) in order to control intracellular calcium levels. Wnt ultimately causes the release of IP3 which then binds to the receptor IP3R which causes calcium to be released from the ER. Problems with this calcium release triggered by IP3R were put forward by Prof Gargus as a possible nexus where different genetic types of autism come together, but he does not translate this thinking into potential therapies. IP3R has been covered in earlier posts.  

Is dysregulated IP3R calcium signaling a nexus where genes altered in ASD converge to exert their deleterious effect?

The Excitatory/Inhibitory Imbalance – GABAA stabilization via IP3R

Wnt signalling also plays a role in dendritic spine morphology, which I wrote about at length previously. In autism the synaptic pruning process does not result in the optimal structure, but even after this process has been completed it is possible to fine tune brain function by changing the shape of the dendritic spines that remain. This dendritic spine morphology can be modulated by Wnt signalling. 
It appears that either a Wnt activator or a Wnt inhibitor may be required to improve dendritic spine morphology depending on the person and the nature of their dysfunction. In a bipolar mouse model, lithium was used as a Wnt activator to create a denser structure of dendritic spines and a more functional mouse. My assumption is that in my case I need a Wnt inhibitor. This is the same situation we have observed with the better known mTOR pathway, where some people are hypo while others are hyper.
Many drugs that have some effect in autism do play a role in Wnt signalling, even Atorvastatin, in my Polypill, has an inhibitory effect.
Wnt signalling is a conserved evolutionary pathway so it is present in everything from fruit flies to humans. It plays a role in many cancers, type 2 diabetes and it seems in neurological conditions such as autism, bipolar and schizophrenia.
My earlier posts on Wnt and PAK1 ended up with 3 options:-

·      Ivermectin

·      FRAX486

·      Bio30 Propolis

The Bio30 propolis is put forward as a PAK inhibitor, but I think it is too weak unless used in huge quantities. I did try BIO 30 and I think it may have had a marginal effect, but it is expensive and you need a lot of it.
So I think Mebendazole, as a Wnt inhibitor, looks like an alternative more practical route to achieve the same thing.

Roche do not seem to be commercializing FRAX486, whereas Mebendazole is sitting in the OTC part of most pharmacies across the world (excluding the USA). Under the brand name Vermox, pharmacies in New Zealand legally sell it worldwide.
If Mebendazole has potency to have an anti-cancer effect, like FRAX486, then it should have potency to give an autism effect.

Note that some people may need a Wnt activator.
You can read all about Wnt at this Stanford lab here.


Back to Cancer
Cancer appears to be more common among people with autism and so it was to be expected that some readers of this blog are treating both autism and some type of cancer.

It does seem that there is scope to repurpose some very common generic drugs to improve the prognosis of many cancers. As with autism, there is great resistance among mainstream clinicians to do this.
As with autism, there are hundreds of sub-types of cancer and so it is not easy to collect relevant evidence, even in the best circumstances, so often it is a case of anecdotes. It is hard to prove anything conclusively, but some very expensive cancer therapies are only minimally effective. As with autism, even a moderate chance of success is worth pursuing and none of the mentioned potentially “repurposable” drugs have more than trivial side effects. Many ultra-expensive dedicated cancer drugs have side effects that are far from trivial and some have very limited benefit.

It seems that while many clinicians are aware of the potential benefit of these off-label therapies, very few prescribe them. Some seem quite happy if you get them somewhere else, which in the case of Prof Williams (see below) from San Diego means regular trips across the border to a pharmacy in Tijuana, Mexico.

Cimetidine for cancer
I did mention cimetidine in my last post.

Cimetidine (Tagamet) is an H2 antihistamine that lowers acidity in your stomach, but cimetidine does much more, it even increases your level of estrogen, which may help some autism. The anti-cancer effects of cimetidine are well documented, they come in part from its own actions and in part from interfering with how the prescribed cancer drugs are metabolized. Cimetidine increases the plasma concentration of numerous drugs including some anticancer drugs.
There are various different theories to explain the anticancer effects of cimetidine itself, but what looks clear is that it improves the prognosis of many types of cancer.
You might expect it to have a negative effect on the types of cancers that have estrogen receptors.

Desloratadine for cancer
On the subject of antihistamines, the OTC second generation antihistamine Desloratadine (Clarinex, Aerius)  has been shown to improve outcomes in breast cancer. As usual drugs have multiple modes of action and so the anticancer effect may have nothing to do with histamine. The data to support this anticancer effect comes from Sweden and the data is presented in the patent application below.


Perhaps one mode of anti-cancer action is the following one:-



Generic drugs with anti-cancer properties
So far we have covered in the last post and this one:

·      Ivermectin

·      Mebendazole (Vermox)

·      Albendazole

·      Cimetidine (Tagamet)

·      Statins (particularly Simvastatin, but also Atorvastatin)

·      Metformin

·      Desloratadine (Clarinex, Aerius)

·      Suramin (but use is limited by toxicity at high doses)

An antifungal treatment, Itraconazole, has an effect inhibiting hedgehog signaling, relevant to many cancers and has been shown to have some effect on prostate and breast cancer in particular. This might also have an effect in some autism where hedgehog signalling is elevated.
Itraconazole does not work well with drugs that lower stomach acidity, like H2 antihistamines and PPIs.


The Polypill approach to cancer
I was looking for information to support the possible effect of Mebendazole in autism and I came across a great example of someone with my approach treating his brain tumor. With good sense he was seeking to follow mainstream therapy, but to supplement it with science based off-label therapies.


The Drugs in Question: the evidence for and against

Metformin: Several studies suggest that tumors grow more slowly in cancer patients who take this anti-diabetic drug. Early-stage clinical trials are investigating its potential to prevent various cancers including prostate, breast, colorectal and endometrial.

Statins: Preclinical studies suggest these cholesterol-lowering heart drugs may prevent various cancers and stop them spreading. One recent meta-analysis associated a daily statin with a significant risk reduction of liver cancer.

Mebendazole: There is evidence this drug – usually prescribed to treat parasitical worm infections — may inhibit cancer cell growth and secondary tumors, though no clinical trials have been completed.

Cimetidine: This over-the-counter antacid has direct anti-proliferative effects on cancer cells, inhibits cell adhesion, reduces tumor angiogenesis (growth of blood vessels essential to a developing tumor) and also boosts anti-cancer immunity in various cancers.

Itraconazole: The common anti-fungal treatment is also thought to be anti-angiogenic and has shown promise as an agent for prostate cancer, non-small cell lung cancer and basal cell carcinoma, the most common kind of skin cancer.

Isotretinoin: This acne drug, marketed as Accutane, is occasionally used to treat certain skin cancers and neurological cancers as well as to prevent the recurrence of some brain tumors, although some studies suggest it is ineffective.

Professor Williams is not a doctor, but that did not stop him reading the research.
His choice of cheap generic off-label anti-cancer drugs looks pretty smart to me. He is still alive two decades after he “should” have been dead. It may all be a happy coincidence and perhaps he would have survived his orange-sized brain tumor without his own interventions. 

There are numerous alternative therapies for cancer and some people do even forgo conventional therapies to treat themselves, which looks very foolish to me.
Personally I would put my faith in science and that does not necessarily mean just medicine. Medicine is based on an evidence-based selective interpretation of often out of date science. So in some fields, medicine works just great, but in complex areas like cancer or anything to do with the brain, medicine lags decades behind science.

As Prof Williams learned, evidence is great as long as you are not going to die before someone collects it. If you have only a year to live what do you really care about any minor side effects metformin, simvastatin or cimetidine may have?
There are some apparently nutty therapies for cancer, just as there are for autism; I think someone should investigate them anyway, just in case someone has stumbled upon something effective by accident.