Department Practice of Urologie, Bahnhofstr 1, 30159 Hanover, Germany
* Corresponding author Email:
Modern theories on the carcinogenesis cannot explain the process of cancerous progression, i.e. the process of creation of new cancerous cell clones. This paper discusses cancerogenic hypercycle treatment.
The hypothesis on the cancerous hypercycle explains this process by the creation of a new form of inner-cell self-organization out of the chaos generated by disintegration and competition of the DNA and the RNA worlds. This process develops based on laws of synergetic and can be subject to computer modelling.
Evaluation of hypothesis
The molecular biology data confirm this hypothesis.
Computer modelling of this process will allow to detect cancer early, to elaborate new methods of its control and treatment.
Evolutional life on earth has developed by self-organizing in the direction from the simplest RNA replication forms to complex hierarchical cell structures which ensured the transmission of genetic information by DNA replication. According to the states of evolutional chemistry, primary forms of life self-organization were autocatalytic chemical reactions, i.e. reactions in which the catalyst for their processing was generated in the process of these reactions themselves, and for which it was not required from the outside.
In the process of further evolutional development and specialization of biochemical reactions, specialized proteins took on the role of catalysts–enzymes, and the role of genetic information carrier remained to be performed by RNA. These autocatalytic reactions are already able to enter in interactions with each other and generate more complex structures, referred to as hypercycles. A hypercycle is a means of merging self-reproducing macromolecules in closed autocatalytic chemical cycles. A hypercycle is several cyclic reactions organized in the way that by-products of one reaction are catalysts of the other one, and the last reaction produces catalysts for the first one. This is a means of merging of self-reproducing units in a new stable system capable of evolution (pp.18–29). One of the reasons for competition and cooperation of two cyclic RNA replication reactions and their merging in a hypercycle is the coding by these RNA’s of enzymes which are able to replicate the RNA of the one as well as of the other cyclic reaction, i.e. such enzymes are shared by both reactions. These enzymes hence merge two cyclic reactions in a hypercycle(pp.218–219). This mechanism can play an important role in cancerous hypercycle development and in RNA interference, which we will show below in the section “RNA interference as a cancerous hypercycle”.
Our hypothesis consists of the assumption that, the mechanism of hypercycles creation is the basis of cancer creation.
The author has referenced some of its own studies in this hypothesis. The protocols of these studies have been approved by the relevant ethics committees related to the institution in which they were performed.
Cyclic RNA replication reactions which serve as the base for a hypercycle have not disappeared and serve as a basis for a more highly developed life form in the cell. An example for such a cyclic reaction with auto-enhancing is phage replication in a bacterial cell (pp.26–27).
To simplify the explanation, we subsequently refer to these simplest RNA replication forms as RNA world.
A developed life form includes a world in which the role of the genetic information carrier is played by the DNA, and the role of the catalyst for DNA replication is played by specialized proteins generated by transcription and translation processes (subsequently: “DNA world”).
A DNA world is a system of simple replicative units (DNA replication and RNA replication) separated from each other by a membrane. If these simple replicative units merge with each other by means of shared enzymes which produce impact on one as well as on the other replicative unit or by RNA interference (this fermentative mechanism stands separately and is examined later), a hypercycle is generated. If the result of such a merging is RNA world progress which displaces the DNA world, such a hypercycle becomes a cancerogenic hypercycle. The cancerogenic nature of such a hypercycle can be explained by the fact that RNA replication is a much more mutagenic process than DNA replication. This mutagenic process spreads on the DNA world by epigenetic reprogramming of DNA, i.e. by DNA methylation.
The creation of a hypercycle according to the first characteristic, i.e. based on shared enzymes, can only take place in the absence of a nuclear membrane, which is the case during a cell division cycle or when the membrane is damaged. For a cancerous tumour, generation of pathological forms and prolonging of the mitosis metaphase is characteristic.
This is why the time of absence of a cell membrane in the mitosis process in a cancerous cell increases in comparison to such a time in a normal cell, and the forming of a cancerogenic hypercycle is facilitated.
Examples of a hypercyclic link based on shared ferments are considered in the chapter “shared ferments as a kind of hypercyclic link of a cancerous hypercycle”.
The creation of a hypercycle according to the second characteristic, i.e. by RNA interference, takes place in the presence of a nuclear membrane. No conditions of membrane absence or damage are required. RNA interference is also a fermentative mechanism which is shared by two simple cyclic units. An example of a hypercyclic link based on RNA interference is presented in the chapter “RNA interference as a form of hypercyclic link of a cancerous hypercycle”.
Our hypothesis assumes that the RNA world, remaining in the cell and integrated in inner cell processes, begins to play the leading role in cancerogenesis as a result of disintegration and competing interaction with the DNA world by its ability of self-organization and autonomous evolution after the loss of control over it by the DNA world. Resulting from this competition, replacing and displacing of the DNA world by the RNA world takes place, a degradation process when a more highly organized form of matter is replaced by a less organized form. This replacing and displacing takes place by the mutagenic impact of one of the components of the RNA world–enzyme which fulfils the replication, and/or of the mutating RNA itself, by the mechanism of RNA interference which is considered below. The mutagenic impact expressed in DNA methylation entails epigenetic DNA reprogramming in such a way that the genes which enhance the RNA world are subject to expression. Pathological DNA methylation and the displacing of the DNA world by the RNA world as a result of competition for energetic cell resources, whose lack entails the limitation of the possibility for the DNA world to self-restore, entails genetic instability and generation of DNA mutations. As a result of this process, the DNA world gains characteristics which are innate to the RNA world–mutagenesis character and a progressing development with generation of new cell clones, which is, in essence, generation of new life species.
Therefore, the cancerogenesis process is regarded by us not as a unique incident in the kind of one or several DNA mutations, but as a process of continuous incidents of epigenetic modifications in the DNA, whose uninterrupted nature and continuousness is ensured by the RNA world progress and spreading, and which is referred to as hypercycle. The involving of cell structures in it, as well as the involving of the nuclear DNA itself, is referred to as cancerogenic hypercycle.
Our hypothesis belongs to the group of epigenetic hypotheses of cancer generation as cancer generation is explained by it with processes which take place not in the nuclear DNA, but in the cell cytoplasm. DNA mutations which take place in cancerogenesis are regarded by us as a secondary process.
Some authors of the epigenetic theory of cancer generation claim that DNA perturbation in the cell nucleus takes place under the impact of an “epigenetic code“, but do not explain the origin of this epigenetic code. The newness of our hypothesis is the explanation of the origin of this “code“ as a cancerous hypercycle code able to generate and develop autonomously and spontaneously in the cell.
The questions how and why the processes of DNA world cooperation and generation of primary life forms are replaced by competition processes were discussed in our precedent work.
Here, we would just like to add that a cancerous cell, as well as any life form, is a dissipative system from the synergetic point of view. The difference of a dissipative system of a cancerous cell from a dissipative system of a normal cell is, firstly, the organization of a new order based on RNA world progress, and, secondly, the higher degree of entropy as a measurement of chaos, i.e. freedom variations for individual units of this system. This is expressed in cell anaplasia, in expression of genes not innate to a normal cell, in the fact that organelles of a cancerous cell stop to fulfil the functions normally innate to them: mitochondria stop to supply the cell via aerobic glycolysis, lysosomes stop to participate in apoptosis. This is expressed i.e. in the relative autonomization of the RNA world as a result of perturbation of links between elements of the DNA world.
The generation of cancer as a new form of a dissipative system is subject to synergetic laws. Due to the chaos generated as a result of perturbation of the DNA world control over the RNA world and competition of two systems, here the DNA and RNA worlds, resulting from a coincident fluctuation whose role can be played by cancerogenic factors, by a Thom catastrophe, and having bypassed the bifurcation point, an irreversible state of a new balance is created, i.e. a new dissipative system in which there will be different order parameters than in the dissipative DNA world system. The generation of such a new dissipative system is probable and not predetermined.
Laws of synergetic determine cancer diagnostic and treatment, which is scrutinized below.
dsRNA can be a cyclic reaction which serves as the base for a cancerogenic hypercycle created by RNA interference, and any ferment able to cause RNA-dependent RNA replication can be the enzyme. Such an enzymatic activity is possessed by RNA-dependent RNA polymerase (RdRP), DNA-dependent RNA polymerase II, retroviral reverse transcriptases–reverse transcriptase (also known as revertase or RNA-directed DNA polymerase. (Subsequently: “shared hypercycle enzymes, abbr. SHE”). Presence of SHE ferments able to catalyse different cyclic reactions is a typical characteristic of a hypercyclic link. Creation of a hypercycle according to the first characteristic mentioned above can take place based on such a hypercyclic link. This is why we can regard cyclic reactions of dsRNA replication and mRNA (iRNA) replication as a component of a hypercycle in which the activity of these ferments can entail competition of its components. This particular case deals with merging in a hypercycle of such cyclic reactions as dsRNA replication, iRNA replication and DNA replication. Hence, the cancerous cell has at least three cyclic reactions able to create a hypercycle via the shared enzymes. The first one is siRNA replication, the second one is iRNA replication reaction, and the third one is DNA replication reaction. It is relatively simple to evaluate a hypercycle composed of two cyclic reactions in which the ferment of one cyclic reaction can cause RNA replication of the other cyclic reaction, and the ferment of the second cyclic reaction can only cause the replication of its own RNA and cannot replicate the RNA of the first cyclic reaction. If both ferments of the hypercycle promote the replication of one of two RNAs more, the winner in the competition of these two cyclic reactions will be this particular RNA replication reaction(p.219). In the case of a hypercycle with two cyclic reactions–in our case, i.e. cyclic siRNA replication reaction and iRNA replication–the winner of the competition will be siRNA, i.e. the RNA world, as RdRP replicates only the siRNA, but cannot replicate iRNA. Yet, the DNA-dependent RNA polymerase II can replicate iRNA as well as siRNA. Hence, in sum, these two ferments promote siRNA than iRNA more.
If a third cyclic reaction joins the hypercycle, in our case a revertase able to replicate siRNA as well as a virus, the advantage of the RNA world even grows as a third ferment and is added which enhances siRNA replication.
Hence, the proposed hypothesis provides a new, different explanation of the viral theory of cancer generation: cancer is generated resulting from enhancement of the cancerous hypercycle by a cyclic RNA virus replication reaction.
The answer to the question whether these ferments can cause, besides specific functions of replications of correspondent nucleic acids innate to them, also DNA methylation, remains open. Yet, such a mechanism is not excluded as cases in the nature are known of DNA methylation in the absence of methyl transferase, which was earlier considered to be indispensable for methylation.
If a cancerous hypercycle of such form is limited to the process of displacing the DNA world without methylation and epigenetic DNA reprogramming only, in this case, damage of the DNA world also takes place due to competition for energetic cell resources and, as a consequence, limited self-restoration possibility of the DNA world.
To understand the development mechanism of a cancerogenic hypercycle via RNA interference, it is necessary to stop shortly at how RNA interference functions in a normal cell.
Normally, the transcription and translation regulation runs in the way of pre-miRNA–interaction with Dicer–interaction with RNA-induced silencing complex (RISC). Hence, the “epigenetic code” of a normal cell is realized (Figure 1).
Transcription und translation regulation through RNA interference in a normal cell. Border between DNA world (left) and RNA world (right below) is indicated by a dotted line.
Pre-miRNA as well as dsRNA interact with the same structures in the cell cytoplasm–with the protein complex Dicer and the RISC complex, whose central element is endonuclease which belongs to the proteins family Argonaute (Ago).
These two classes of short RNAs, miRNA and siRNA, are able to compete for a place in the same effectorial complexes, i.e. Dicer and RISC are the shared element which links two cyclic reactions: miRNA replication reaction and dsRNA replication reaction, and hence is a form of a hypercyclic link.
A cancerous hypercycle based on RNA interference is created in the following way (see Figure 2).
Spreading of the carcinogenic hypercycle (Rd-dsRNA) on translation through RNA interference in a cancerous cell. Border between DNA world (left below) and RNA world (right) is indicated by a dotted line.
Two elements–Dicer and RISC–are a place of competing interaction between pre-miRNA and dsRNA where competition for replacing the miRNA normally regulating the gene transcription and translation by the cancerogenic dsRNA takes place. After such a replacing, dsRNA becomes an anti-sense siRNA chain, the latter one methylates and reprograms the DNA in the cell nucleus on the one hand, i.e. it modifies the normal “epigenetic code”, and depresses the translation by binding it with the correspondent complementary sequence in the mRNA composition on the other hand.
siRNAs are capable of building long RNA molecules. Hence, they are able to be primers for synthesis of new RNAs on a single-stranded and/or a double-stranded RNA matrix of the RdRP.
Prolonging siRNA products are double-stranded RNA themselves. This is why they are subject to further post-transcriptional modification with creation of “secondary” siRNAs and a probable participation of Dicer. Hence, the RNA interference process looks like a degrading polymerase chain reaction in which primary siRNA molecules, being primers for synthesis of new double-stranded RNA molecules, entail creation of secondary siRNAs.
This process can be autocatalytic, i.e. capable of autonomous evolution, and correspond to a hypercycle if one of the products of this cyclic reaction is SHE generation.
Such a cycle can continue indefinitely as long as RNA is present which is able to be a matrix for siRNA primers.
Therefore, the cyclic dsRNA-SHE reaction, as a result of gaining a competing advantage over the cyclic translation miRNA-mRNA degradation control reaction, the RNA interference mechanism displaces and replaces the latter one. Reasons for generation of a competing advantage of the RNA world over the DNA world were indicated in our precedent work. On a molecular level, this is expressed in decrease of miRNA concentration and increase of siRNA concentration.
In the case of the creation of a cancerous hypercycle by RNA interference, siRNA increase at the background of miRNA decrease takes place. Such a profile speaks in favour of our hypothesis. Some facts confirming such a development of incidents in a cancerous cell are already proven.
Such facts include high dsRNA mutability and its capability of an autonomous replication, independent of the DNA world.
The capability of competition for the epigenetic regulation of transcription and translation between the siRNA of a cancerous hypercycle and the miRNA of the DNA world via the interference mechanism mentioned above in the section “RNA interference as a form of a hypercyclic link of a cancerogenic hypercycle” is also confirmed.
The fact of miRNA depression in a cancerous cell is also confirmed.
Therefore, there are at present enough facts indicating a competing interaction between siRNA–RdRP and DNA world for the epigenetic control over the transcription and translation in a cell, and also indicating the fact that this control is, in a cancerous cell, under the regulation of a new RNA world order organizer represented by the siRNA–RdRP hypercycle. The quoted facts also indicate the displacing and replacing of miRNA by the product of the cancerous siRNA hypercycle, i.e. displacing and replacing of the DNA world by the RNA world.
The quoted facts are in favour of our hypothesis, but they cannot serve as its definite evidence. In general, our hypothesis cannot be proven based on a biochemical analysis method, i.e. method of separating a whole system to its component elements. A cancerous hypercycle can be a quite complex generation including several cyclic reactions linked to each other by hypercyclic reactions based on shared ferments as well as on RNA interference. A simple concentration evaluation of hypercycle components cannot provide us an image of the hypercycle as a dynamically developing structure. As our hypothesis assumes the generation of a new system from the elements of the precedent system, the proving of the hypothesis requires a synthesis method, a computer system modelling method, and comparison of this virtual model to the biological model. For this, a biological model should be chosen–an animal with a certain cancer form, the miRNA and siRNA concentrations in it as well as concentration of ferments replicating those RNAs should be examined, i.e. the biochemical profile of RNA and enzymes is to be examined. This profile should be compared to the correspondent profile of the control group of healthy animals. Based on the evaluated differences, a mathematical computer model of a cancerous hypercycle can be constructed and virtual experiments can be conducted, depressing the activity of such or such enzymes of the hypercycle or modifying in a certain way other parameters of cyclic reactions (pH, concentration of chemical agents participating in the reaction and other). It should be mentioned that there is already experience of mathematical modelling of hypercycles (pp.80–175). Hence, it can be clarified which impact must be made on a cancerogenic hypercycle to create a Thom catastrophe with the goal to create a new dissipative system in which the DNA world would gain a selective advantage and prevail over the RNA world, and the generation probability of this new dissipative system can also be calculated. Taking into account the gained result, the same action should be conducted on a real biological model and the gained results should be compared. The impact control and the evaluation of its effectiveness are conducted by scrutinizing the RNA profile and the enzymes.
Taking into consideration the fact that the DNA methylation profile (“epigenetic code”) in some mice tumours, e.g. such as bowel cancer, corresponds in a great measure to the DNA methylation image of the human bowel cancer, it is to be expected that the cancerogenic hypercycles structure determining such a similar “epigenetic code” in both cases will also be similar.
Applying such a method, several goals at one time can be achieved. The existence of a cancerous hypercycle can be proven as well as new possibilities for cancer diagnostics, prognosis and treatment can be detected.
Acting on the assumption of the hypothesis of cancer generation as a development of a cancerogenic hypercycle, we have to look differently at the impact mechanism of known anti-tumour treatment methods as well as on the cancer diagnostics and treatment strategy. The task of diagnostics becomes to detect the order parameters of the new dissipative system which the cancerous cell is. Such parameters are, most probably, siRNA, miRNA and SHE activity.
The task of treatment becomes the creation of conditions in the cell that would change the competing interaction between the DNA world and the RNA world to a competing advantage in favour of the DNA world. This is the newness of the proposed cancer treatment conception and its difference from the modern cancer therapy: radical healing from cancer is impossible without elimination of the cancerous hypercycle.
Biochemical reactions run in a relatively narrow interval of physical and chemical parameters. To cause a selective effect with the goal of depressing one reaction and promoting the other one, it is necessary to know the difference of physical and chemical parameters of one reaction from those of the other one. Applied to our situation, it is necessary to know the difference of RNA replication parameters from the DNA replication parameters.
One such difference in DNA and RNA world parameters is the fact that the mutations number in RNA replication is significantly higher than the mutations number in DNA replication, and when surpassing a certain threshold of mutations number (p.78), RNA replication becomes impossible, whereas the DNA world is capable of self-restoring.
Assuming this, the tactics of radiation cancer treatment also changes. The treatment task becomes to select a radiation dosage that would, on the one hand, not cause too great a loss for DNA, and on the other hand, destroy the RNA replication hypercycle. This dosage will be knowingly lower than the one used in modern cancer therapy for DNA world destruction with the goal of preventing cell division. The modern tendency of cancer treatment by radiation therapy confirms this theoretic deduction–e.g. prostate cancer treatment is more effective with lower dosages than it was assumed to be earlier.
Target cancer therapy is aimed at elimination of consequences of expression of genes entailing uncontrollable cell division. Target therapy decelerates the development of a cancerogenic hypercycle by eliminating some of its components e.g. expression of genes causing cell division, but it does not completely depress it as the primary cyclic RNA replication reaction continues to cause its impact on DNA methylation and on generation of new DNA mutations.
This is why the main treatment targeted at restoration of the balance between the DNA and the RNA world has to be depression of the RNA world progression and, concretely, of such or such form of cancerogenic hypercycle.
The simplest method is blocking of activation of ferments replicating RNA–RdRP. Amongst preparations able to cause such an impact is pyrogallol. The anti-tumour impact of pyrogallol is already proven.
Elaboration of preparations causing selective depression of cancerogenic hypercycle enzymes can be a perspective direction in cancer treatment.
The process of creation of a new clone of cancerous cells is a process of creation of a new dissipative system based on creation of a carcinogenic hypercycle. This process can be described mathematically and a corresponding model on a computer can be built. Such a modelling will allow to detect cancer early and to elaborate new methods of its control and treatment.
All authors contributed to conception and design, manuscript preparation, read and approved the final manuscript.
All authors abide by the Association for Medical Ethics (AME) ethical rules of disclosure.