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.

Patent - Antihistamine for use in treatment of breast cancer

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

The antihistamines clemastine anddesloratadine inhibit STAT3 and c-Myc activities and induce apoptosis incutaneous T-cell lymphoma cell lines.

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.

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

Zinc, Hedgehog Signaling, Shank2/3, NMDA/AMPA Inactivation and Autism

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 professor who'cured' his cancer with a cocktail of everyday pills and 20 years on remains disease-free

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.

Modulating Wnt Signaling in Autism and Cancer

Source: LDL receptor-related proteins 5 and 6 in Wnt/β-catenin signaling: Arrows point the way

In earlier posts I have covered various signaling pathways such as Wnt, mTOR and the unusually sounding Hedgehog.

You can go into huge detail if you want to understand these pathways, or just take a more superficial view. In most cases, things only start to go wrong if you are hypo/hyper (too little/too much) in these pathways.

We saw with mTOR that most people with autism are likely to have too much activity and so might benefit from mTOR inhibition, but a minority will have the opposite status and stand to benefit from more mTOR activity.

When it comes to Wnt signaling the research suggests the same situation. Wnt signaling is likely to be aberrant, but both extremes exist.

Wnt signaling networks in autism spectrum disorder and intellectual disability

Given the large volume of genetic data, analyzing each gene on its own is not a feasible approach and will take years to complete, let alone attempt to use the information to develop novel therapeutics. To make sense of independent genomic data, one approach is to determine whether multiple risk genes function in common signaling pathways that identify signaling “hubs” where risk genes converge. This approach has led to multiple pathways being implicated, such as synaptic signaling, chromatin remodeling, alternative splicing, and protein translation, among many others. In this review, we analyze recent and historical evidence indicating that multiple risk genes, including genes denoted as high-confidence and likely causal, are part of the Wingless (Wnt signaling) pathway. In the brain, Wnt signaling is an evolutionarily conserved pathway that plays an instrumental role in developing neural circuits and adult brain function.

While the human genetic data is an important supporting factor, it is not the only one. There are a number of mouse genetic knockout (KO) models targeting Wnt signaling molecules, describing molecular, cellular, electrophysiological, and behavioral deficits that are consistent with ASD and ID. Furthermore, the genes involved in Wnt signaling are of significant clinical interest because there are a variety of approved drugs that either inhibit or stimulate this pathway.

There are many drugs developed and tested as modulators of Wnt signaling in the cancer field that could potentially be repurposed for developmental cognitive disorders. In cases where a reduction in Wnt signaling is thought to underlie the pathology of the disorder, usage of compounds that elevated canonical Wnt signaling could be applied. An example of this is GSK-3β inhibitors that have failed in cancer trials but may be effective for ASDs and ID (e.g., Tideglusig, ClinicalTrials.gov identifier: {"type":"clinical-trial","attrs":{"text":"NCT02586935","term_id":"NCT02586935"}}NCT02586935). In cases where elevated Wnt signaling is thought to contribute to disease pathology, there are many potential options to inhibit canonical Wnt signaling using chemicals (Fig. 1) that inhibit the interaction between β-catenin and its targets (e.g., inhibiting β-catenin interaction with the TCF factors), disheveled inhibitors (through targeting of the PDZ domain which generally inhibit the Frizzled–PDZ interaction), and tankyrase inhibitors (e.g., XAV939, which induces the stabilization of axin by inhibiting the poly (ADP)-ribosylating enzymes tankyrase 1 and tankyrase 2)

As autism candidates emerge, cancer pathway rises to top

In recent years, strong autism ties have cropped up for one group of genes in particular: those that make up a well-known signaling pathway called WNT, which also has strong links to cancer. This pathway is especially compelling because some people with autism carry mutations in various members of it, including one of its central players: beta-catenin¹. What’s more, studies from the past year indicate that several of the strongest autism candidate genes, including CHD8 and PTEN, interact with this pathway.

“There might be a particular subgroup of genes associated with autism that could all be feeding into or be regulating this pathway,” says Albert Basson, reader in developmental and stem cell biology at King’s College London, who studies CHD8 and WNT. “That clearly has emerged as a relatively major theme over the last few years.”

The connection between cancer and some autism is over-activated pro-growth signaling pathways. Many signaling pathways have growth at one extreme and cell death at the other. In cancer you actually want cell death to suppress tumor growth; in much autism there is also too much growth.  

Many cancers are associated with elevated signaling of mTOR, Wnt and indeed Hedgehog.  These are targets for cancer drug therapy and so there is already a great deal known.

A complication is that in a developmental neurological condition, like autism, it also matters when these signaling pathways were/are disturbed. For example Wnt signaling is known to play a role in dendritic spines and synaptic pruning, some of this is an ongoing process but other parts are competed at an early age, so it would matter when you intervene to modulate these pathways.

Historically cancer therapies involve potent drugs, often with potent side effects, however in recent years there has been growing awareness that some safe existing drugs can have equally potent anti-cancer effects. Many of these drugs are anti-parasite drugs, but even the very widely used diabetes drug Metformin has been shown to have significant anti-cancer effects, not to forget Simvastatin.

Many autism pathways/genes play a role in cancer (RAS, PTEN) and the upstream targets considered in cancer research are also autism targets.  For example many human cancers are RAS dependent and in theory could be treated by a RAS inhibitor, but after decades of looking nobody has found one. So instead scientists go upstream to find another target that will indirectly reduce RAS. This led to the development of PAK1 inhibitors that will reduce RAS.

RAS plays a role in some types of intellectual disability and indeed autism. The collective term is RASopathy.  Logically, drugs that modulate RAS to treat cancer might be helpful in modulating RAS for some autism.

Most types of cancers are complex and so there are multiple potential targets to attack them, but also the same target can have multiple possible approaches. RAS dependent cancers can be targeted via Wnt and even Hedgehog signaling.

This may sound all very complicated but does it have any relevance to autism?

It apparently does because almost all these pathways are known to be disturbed hypo/hyper in autism.  This means that clever insights developed for cancer can be repurposed for autism.

Anti-parasite drugs and Cancer

It is indeed remarkable how many anti-parasite drugs have an anticancer effect and indeed there is a much maligned theory to justify this.

Clinical Evaluation of a New Form of Cancer Therapy Based on the Principles of Atavistic Metamorphosis

Quite possibly it is just a coincidence.

There are many ways to kill parasites, one of which involves starving them of ATP. ATP is the fuel that is produced in your mitochondria.

Cancer cells and many parasites use a very inefficient way to produce ATP that does not require oxygen. In normal human cells the process followed is known as OXPHOS, by which glucose and oxygen from the blood is converted into ATP (energy) is very efficient. Only when you run low on oxygen, like a marathon runner at the end of the race, can you run into trouble because there is not enough oxygen for OXPHOS.  What happens next is anaerobic respiration, when a different process takes over to make ATP. It is much less efficient and causes lactic acidosis which makes marathon runners' muscles hurt.

A cheap anti-parasite drug Pyrvinium targets anaerobic respiration and starves the parasite of ATP and thus kills it. Another common children’s anti-parasite drug albendazole also works by starving the parasite of ATP.

Other anti-parasite drugs work in different ways.

We already know from the autism trials of Suramin, another anti-parasite drug,  that it works via P2X and P2Y purinergic channels.

Ivermectin  binds to glutamate-gated chloride channels (GluCls) in the membranes of invertebrate nerve and muscle cells, causing increased permeability to chloride ions, resulting in cellular hyper-polarization, followed by paralysis and death.  Fortunately in mammals ivermectin does not cross the BBB.

Ivermectin is also a PAK1 inhibitor and a positive allosteric modulator of P2X7.

Both PAK1 and P2X7 are relevant to many cancers and so not surprisingly research shows that Ivermectin has an anti-cancer effect.

Ivermectin appears to have a positive effect in some autism, but strangely it does not cross the BBB.

Mebendazole is another extremely cheap children’s anti-parasite drug which has remarkable potential anti-cancer properties. It inhibits hedgehog signaling and, via the inhibition of TNIK, it is a Wnt inhibitor.

Unfortunately in the US the private sector has also noticed the anticancer effects of Mebendazole and albendazole and they have recently become astronomically expensive. Mebendazole (MBZ), which costs almost nothing in many countries, now costs hundreds of dollar per dose in the US under the name Emverm. Outside of the US, Mebendazole is OTC in many developed countries. In poor countries it is donated free by big pharma.

In the cancer research they consider taking advantage of the fact that cimetidine (a cheap H2 antihistamine) interacts with Mebendazole to increase its bioavailability. Cimetidine is by chance another generic drug also being considered to be repurposed for cancer.

While some anti-parasite drugs like Suramin have side effects or cannot be taken regularly like Ivermectin, others are seen as safe for continued use even at high doses (e.g. Mebendazole and albendazole).  

Anti-parasite drugs and Autism

Just as many anti-parasite drugs seem to have a positive effect on some cancers it looks likely that the same may be true for autism.  This does not mean that parasites cause either cancer or autism.

We know from Professor Naviaux that some people respond to Suramin.

Two people who comment on this blog have found their child responds to PAK1 inhibitors, one of which is the drug Ivermectin.

There are groups of people on the internet who think parasites cause autism and you will find some of them if you google “autism mebendazole”, but there are some very valid reasons why some people’s autism may respond to mebendazole, but nothing to do with little worms.

Potency of Anticancer drugs

Failed anticancer drugs are already considered as possible drugs to treat neurological conditions.

The same pathways do seem to be involved in some cancer and some neurological conditions, but the severity by which that pathway is affected may be very different, so a new drug may lack potency to treat a type of cancer but be potent enough to benefit others.

In the case of the anti-parasite drugs Ivermectin and indeed mebendazole the dosage being used in current cancer studies are very much higher than normally used.

Very little mebendazole makes its way out of your intestines and so researchers counter this by using a dose 15 times higher and even taking advantage of the interaction with the H2 antagonist cimetidine to boost bioavailability.

The standard human dose of Ivermectin is 3mg, but in the cancer trials (IVINCA trial - IVermectin IN CAncer) in Switzerland and Spain the trial dose is 12, 30 and 60 mg.

So when it comes to autism and the possible repurposing of these drugs, the cancer studies will give valuable safety information, but the likely dose required to fine-tune these signaling pathways will likely be a tiny fraction of the cancer dose.

The newly developed cancer drugs that fail in clinical trials, may have potential in autism but it is unlikely that anyone will develop them, test them and bring them to the market.

The clever thing for autism seems to be to keep an eye on the existing generic drugs considered to benefit the overlapping cancer pathways.

Conclusion

Aberrant Wnt signaling has been identified by researchers as playing a key role in autism; the Simons Foundation is among those now funding further research.

In practical terms you can be either hypo or hyper, but hyper seems more likely. It may be a case of shutting the stable door after the horse has bolted, because the ideal time to modulate Wnt signaling is probably as a baby, or before. Nonetheless some older people may indeed benefit from modulating Wnt; the Simons Foundation must also believe so.

In the case of people with hyperactive Wnt signaling, there is a case to make for the potential use of the cheap anti-parasite drug Mebendazole.

The drug Mebendazole (MBZ) can found in three states/polymorphs called Polymorph A, B or C. This is relevant because they do not cross the blood brain barrier to the same extent.

Brain Penetration and Efficacy of Different Mebendazole Polymorphs in a Mouse Brain Tumor Model  

To treat brain tumors, or indeed potentially some autism, you need MBZ-B or MBZ-C, it looks like MBZ-A does not cross the blood brain barrier.

Fortunately, MBZ-C is  the polymorph found most commonly in generic mebendazole tablets.  

Ivermectin is known not to cross the blood brain barrier but yet has been shown to show anti-tumor activity in brain cancer. The anti-cancer effect is thought to be as a PAK1 inhibitor, but this effect must be occurring outside the brain. Some people do use Ivermectin for autism.

The people using Ivermectin for autism are told they cannot use it continuously. Perhaps as the high dose cancer trials evolve the safety advice may change.

Tideglusib, Repairing Dental Cavities, Wnt signaling, GSK-3 and Autism

Kings College in London seem to be more effective in dentistry than autism; they have just published research showing how they effectively regrew a tooth to repair a cavity.  That is rather clever.

Perhaps soon to be a thing of the past?

Using biodegradable collagen sponges to deliver the treatment, the team applied low doses of small molecule glycogen synthase kinase (GSK-3) inhibitors to the tooth. They found that the sponge degraded over time and that new dentine replaced it, leading to a complete, natural repair.

Natural tooth repair method, using Alzheimer's drug, could revolutionise dental treatments

The full paper is here:- 

Promotion of natural tooth repair by small molecule GSK3 antagonists

All very well, but what has this got to do with Autism?

As regular readers will be aware, autism turns out to be multigenic (it involves lots of different genes) and no single gene seems to account for more than one or two percent of cases.  A small number of any of hundreds of possible genes can be disturbed and then affect so-called signaling pathways  that control our bodies.  These pathways have evolved over millions of years and can seem quite unnecessarily complex.  The pathways overlap with each other and at certain critical points it seems like different genetic dysfunctions can lead to the same dysfunctional point, or nexus.  

We previously saw one such nexus, IPR3, suggested by Gargus:-

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

 but another one may be the Synaptic Wnt/GSK3β signaling hub. 

Synaptic Wnt/GSK3β Signaling Hub in Autism

We came across Wnt signaling in earlier posts.  Among other things, it relates to those RASopathies that often lead to cognitive dysfunction; but RAS dysfunction can also lead to common cancers, so called RAS-dependent cancers.

Wnt signaling is also involved in hair growth and hair greying, as one of our more adventurous readers experienced.  So using a PAK1 inhibitor to modulate the Wnt pathway may make your hair go grey.

BCL-2 is another autism gene that affects hair growth/loss.

It has been suggested by some of the very clever researchers (Chauhan and Chauhan) that the BDNF-Akt-Bcl2 anti-apoptotic signaling pathway is compromised in the brain of autistic subjects.

So while the gene Bcl-2 might be the dysfunction in one per cent of people, in more cases it is the pathway along which Bcl-2 lies, that is the problem.

There is also so called cross-talk between pathways connecting Bcl-2 to RAS.

Then you will see that some drugs affect both Bcl-2 and RAS.  So on the one hand things get much more complicated than just 20,000 different genes, but on the other hand the really good interventions will likely solve multiple dysfunctions. This is why we have talk about a nexus, or hub, where different dysfunctions lead to common points.

It makes sense to focus on identifying the limited number of these hubs, rather than getting lost in thousands of possibly dysfunctional genes. 

GSK-3 (Glycogen synthase kinase 3)

This area is very complex and really only a few people, mainly cancer researchers, and at least one dentist, understand it.

In essence, among other effects, GSK-3 inhibitors activate Wnt signaling. 

Glycogen synthase kinase 3 is a serine/threonine protein kinase that mediates the addition of phosphate molecules onto serine and threonine amino acid residues. First discovered in 1980 as a regulatory kinase for its namesake, Glycogen synthase ^]GSK-3 has since been identified as a kinase for over forty different proteins in a variety of different pathways.  In mammals GSK-3 is encoded by two known genes, GSK-3 alpha (GSK3A) and GSK-3 beta (GSK3B). GSK-3 has recently been the subject of much research because it has been implicated in a number of diseases, including Type II diabetes (Diabetes mellitus type 2), Alzheimer's Disease, inflammation, cancer, and bipolar disorder. 

Glycogen synthase kinase-3 (GSK3):regulation, actions, and diseases

Glycogen synthase kinase-3 (GSK3) may be the busiest kinase in most cells, with over 100 known substrates to deal with. How does GSK3 maintain control to selectively phosphorylate each substrate, and why was it evolutionarily favorable for GSK3 to assume such a large responsibility? GSK3 must be particularly adaptable for incorporating new substrates into its repertoire, and we discuss the distinct properties of GSK3 that may contribute to its capacity to fulfill its roles in multiple signaling pathways. The mechanisms regulating GSK3 (predominantly post-translational modifications, substrate priming, cellular trafficking, protein complexes) have been reviewed previously, so here we focus on newly identified complexities in these mechanisms, how each of these regulatory mechanism contributes to the ability of GSK3 to select which substrates to phosphorylate, and how these mechanisms may have contributed to its adaptability as new substrates evolved. The current understanding of the mechanisms regulating GSK3 is reviewed, as are emerging topics in the actions of GSK3, particularly its interactions with receptors and receptor-coupled signal transduction events, and differential actions and regulation of the two GSK3 isoforms, GSK3α and GSK3β. Another remarkable characteristic of GSK3 is its involvement in many prevalent disorders, including psychiatric and neurological diseases, inflammatory diseases, cancer, and others. We address the feasibility of targeting GSK3 therapeutically, and provide an update of its involvement in the etiology and treatment of several disorders.

GSK-3 and Autism

The good news is that the Alzheimer’s researchers have already developed a GSK-3 inhibitor, the current favourite is called Tideglusib.  This is also the one the clever dentists at King’s College used.

Researchers in Santiago, Chile, have proposed the role of GSK-3 in the onset and development of ASDs through direct modulation of Wnt/β-catenin signaling.

Synaptic Wnt/GSK3β Signaling Hub in Autism

 Figure 1: Wnt/β-catenin signaling in ASDs. Wnt binding to FZD-LRP5/6 complex receptor at the membrane recruits the destruction complex and inhibits GSK3β activity thus stabilizing β-catenin in the cytoplasm and nucleus. Activation of the Wnt/β-catenin pathway facilitates synaptic plasticity through the activation of voltage gated ion channels that allows activation of CAMK and CREB mediated transcription. Mutations in TSC associated with ASD prevent β-catenin degradation which results in a gain of function of the Wnt pathway. In the presynaptic terminal cadherin mediated cell adhesion between synapses is weakened by phosphorylation of β-catenin and synaptic vesicle clustering is enhanced through DVL1. Clustering is also dependent on NLGN/NRXN cell adhesion complexes. Both lithium (LiCl) and VPA activate Wnt/β-catenin signaling through inhibition of GSK3β activity. Conversely, in the absence of a Wnt ligand, activated GSK3β targets β-catenin for proteosome-mediated degradation. Mutations associated with DISC1 fail to inhibit GSK3β and thus activate Wnt/β-catenin pathway. In the presynaptic side Wnt signaling buffering of synaptic vesicles is inhibited and adherens junctions mediated by cadherins are strengthened.

This becomes more interesting because a clinical trial has already been put in motion to trial Tideglusib in autism.  I am not sure if the Canadian researchers are just trying an Alzheimer’s drug on the off-chance it might help autism, or whether they are really up to speed with their Wnt signaling pathway.  I suspect the former, but it does not really matter.

Tideglusib vs. Placebo in the Treatment of Adolescents  With Autism Spectrum Disorders (TIDE)

This might be of interest to our reader Alli in Switzerland.

Conclusion 

It pays to read the science reports that appear to have nothing to do with autism.

Sense, Missense or Nonsense - Interpreting Genetic Research in Autism (TCF4, TSC2 , Shank3 and Wnt)

Some clever autism researchers pin their hopes on genetics, while some equally clever ones are not convinced.

One big problem is that genetic testing is still not very rigorous, it is fine if you know what you are looking for, like a specific single gene defect, but if it is a case of find any possible defect in any of the 700+ autism genes it can be hopeless.

Most of the single gene types of autism can be diagnosed based on known physical differences and then that specific gene can be analyzed to confirm the diagnosis.

Today’s post includes some recent examples from the research, and they highlight what is often lacking - some common sense.

There are numerous known single gene conditions that lead to a cascade of dysfunctions that can result in behaviors people associate with autism.  However in most of these single gene conditions, like Fragile X or Pitt-Hopkins, there is a wide spectrum, from mildly affected to severely affected.

There are various different ways in which a gene can be disturbed and so within a single gene condition there can be a variety of sub-dysfunctions.  A perfect example was recently forwarded to me, a study showing how a partial deletion of the Pitt Hopkins gene (TCF4) produced no physical features of the syndrome, but did unfortunately produce intellectual disability.

The study goes on to suggest that “screening for mutations in TCF4 could be considered in the investigation of NSID (non-syndromic intellectual disability)”

Partial deletion of TCF4 in three generation family with non-syndromic intellectual disability, without features of Pitt-Hopkins syndrome

This all matters because one day when therapies for Pitt Hopkins are available, they would very likely be effective on the cognitive impairment of those with undiagnosed partial-Pitt Hopkins.

Another reader sent me links to the studies showing:-

Rapamycin reverses impaired social interaction in mouse models of tuberous sclerosis complex.

Reversal of learning deficits in a Tsc2+/- mouse model of tuberous sclerosis.

But isn’t that Tuberous sclerosis (TSC) extremely rare? like Pitt Hopkins.  Is it really relevant?

Tuberous sclerosis (TSC)  is indeed a rare multisystem genetic disease that causes benign tumors to grow in the brain and on other vital organs such as the kidneys, heart, eyes, lungs, and skin. A combination of symptoms may include seizures, intellectual disability, developmental delay, behavioral problems, skin abnormalities, and lung and kidney disease. TSC is caused by a mutation of either of two genes, TSC1 and TSC2, 

About 60% of people with TSC have autism (biased to TSC2 mutations) and many have epilepsy.

How rare is TSC?  According to research between seven and 12 cases per 100,000, with more than half of these cases undetected.  

Call it 0.01%, rare indeed.

How rare is partial TSC?  What is partial TSC?  That is just my name for what happens when you have just a minor missense mutation, you have a mutation in TSC2 but have none of the characteristic traits of tuberous sclerosis, except autism.

In a recent study of children with autism 20% has a missense mutation of TSC2. 

Not so rare after all.

Mutations in tuberous sclerosis gene may be rife in autism

Mutations in TSC2, a gene typically associated with a syndrome called tuberous sclerosis, are found in many children with autism, suggests a genetic analysis presented yesterday at the 2016 International Meeting for Autism Research in Baltimore.

The findings support the theory that autism results from multiple ‘hits’ to the genome.

Tuberous sclerosis is characterized by benign tumors and skin growths called macules. Autism symptoms show up in about half of all people with tuberous sclerosis, perhaps due to abnormal wiring of neurons in the brain. Tuberous sclerosis is thought to result from mutations in either of two genes: TSC1 or TSC2.

The new analysis finds that mutations in TSC2 can also be silent, as far as symptoms of the syndrome go: Researchers found the missense mutations in 18 of 87 people with autism, none of whom have any of the characteristic traits of tuberous sclerosis.

“They had no macules, no seizure history,” says senior researcher Louisa Kalsner, assistant professor of pediatrics and neurology at the University of Connecticut School of Medicine in Farmington, who presented the results. “We were surprised.”

The researchers stumbled across the finding while searching for genetic variants that could account for signs of autism in children with no known cause of the condition. They performed genetic testing on blood samples from 87 children with autism.

Combined risk:

To see whether silent TSC2 mutations are equally prevalent in the general population, the researchers scanned data from 53,599 people in the Exome Aggregation Consortium database. They found the mutation in 10 percent of the individuals.

The researchers looked more closely at the children with autism, comparing the 18 children who have the mutation with the 69 who do not.

Children with TSC2 mutations were diagnosed about 10 months earlier than those without a mutation, suggesting the TSC2 mutations increase the severity of autism features. But in her small sample, Kalsner says, the groups show no differences in autism severity or cognitive skills. The researchers also found that 6 of the 18 children with TSC2 mutations are girls, compared with 12 of 69 children who don’t have the mutation.

TSC2 variants may combine with other genetic variants to increase the risk of autism. “We don’t think TSC is the sole cause of autism in these kids, but there’s a significant chance that it increases their risk,” Kalsner says.

Effects of Combining Rapamycin and Resveratrol on Apoptosis and Growth of TSC2-Deficient Xenograft Tumors

"hyperactivation of the mechanistic target of rapamycin complex 1 (mTORC1) is a consequence of tuberous sclerosis complex (TSC) 1/2 inactivation."

"the combination of rapamycin and resveratrol may be an effective clinical strategy for treatment of diseases with mTORC1 hyperactivation."

So for the 20% of autism with partial TSC, so-called Rapalogs and other mTOR inhibitors could be helpful, but Rapalogs all have side effects.

One interesting option that arose in my earlier post on Type 3 diabetes and intranasal insulin is Metformin. The common drug used for type 2 diabetes.

 

Metformin regulates mTORC1 signaling (but so does insulin).

'Metformin activates AMPK by inhibiting oxidative phosphorylation, which in turn negatively regulates mTORC1 signaling via activation of TSC2 and inhibitory phosphorylation of raptor. In parallel, metformin inhibits mTORC1 signaling by suppressing the activity of the Rag GTPases and upregulating REDD1."

Source:  Rapalogs and mTOR inhibitors as anti-aging therapeutics

Clearly you could also just use intranasal insulin.  It might be less potent but should have less side effects because it acting only within the CNS (Metfornin would be given orally).

The Shank protein and the Wnt protein family

Mutations in a gene called Shank3 occur in about 0.5 percent of people with autism.  
But what about partial Shank3 dysfunction?

Shank proteins also play a role in synapse formation and dendritic spine maturation.

Mutations in this gene are associated with autism spectrum disorder. This gene is often missing in patients with 22q13.3 deletion syndrome

Researchers at MIT have just shown, for the first time, that loss of Shank3 affects a well-known set of proteins that comprise the Wnt signaling pathway.  Without Shank3, Wnt signaling is impaired and the synapses do not fully mature.

Neuroscientists illuminate role of autism-linked gene

“The finding raises the possibility of treating autism with drugs that promote Wnt signaling, if the same connection is found in humans”

I have news for MIT, people already do use drugs that promote Wnt signaling, FRAX486 and Ivermectin for example.  All without any genetic testing, most likely.

Reactivating Shank3, or just promote Wnt signaling

The study below showed that in mice, aspects of autism were reversible by reactivating the Shank3 gene.  You might expect that in humans with a partial Shank3 dysfunction you might jump forward to the Wnt signaling pathway and intervene there.

Mouse study offers promise of reversing autism symptoms

One reader of this blog finds FRAX486 very helpful and to be without harmful side effects.  FRAX 486 was recently acquired by Roche and is sitting over there on a shelf gathering dust.

Where from here?

I think we should continue to look at the single gene syndromes but realize that very many more people may be partially affected by them.

Today’s genetic testing gives many false negatives, unless people know what they are looking for; so many dysfunctions go unnoticed.

This area of science is far from mature and there may be many things undetected in the 97% of the genome that is usually ignored that affect expression of the 3% that is the exome.

So best not to expect all the answers, just yet, from genetic testing; maybe in another 50 years.

Understanding and treating multiple-hit-autism, which is the majority of all autism, will require more detailed consideration of which signaling pathways have been disturbed by these hits.  There are 700 autism genes but there a far fewer signaling pathways, so it is not a gargantuan task.  For now a few people are figuring this out at home.   Good for them.

I hope someone does trials of metformin and intranasal insulin in autism.  Intranasal insulin looks very interesting and I was surprised to see in those earlier posts is apparently without side effects.

The odd thing is that metformin is indeed being trialed in autism, but not for its effect on autism, but its possible effect in countering the obesity caused by the usual psychiatric drugs widely prescribed in the US to people with autism.

My suggestion would be to ban the use of drugs like Risperdal, Abilify, Seroquel, Zyprexa etc.

Vanderbilt enrolling children with autism in medication-related weight gain study

Here are details of the trial.

Treatment of Overweight Induced by Antipsychotic Medication in Young People With Autism Spectrum Disorders (ASD) (MET)

Metformin will be dispensed in a liquid suspension of 100 mg/mL. For children 6-9 years of age, metformin will be started at 250 mg at their evening meal for 1 week, followed by the addition of a 250 mg dose at breakfast for 1 week. At the Week 2 visit, if metformin is well-tolerated, the dose will be increased to 500 mg twice daily. For children from 10-17 years of age, metformin will be started at 250 mg at their evening meal for 1 week, followed by the addition of a 250 mg dose at breakfast for 1 week. At the Week 2 visit, if metformin is well-tolerated, the dose will be increased to 500 mg twice daily. At the Week 4 visit, if metformin is well-tolerated, the dose will be increased to 850 mg twice daily.