Physio-mitotic theory and a new concept of cancer development

Amplification and invasiveness of epithelial progenitors during gastric carcinogenesis in trefoil factor 1 knockout mice

OBJECTIVE

It is not known whether or not epithelial progenitors of the pyloric antrum are involved in gastric carcinogenesis. Normally, these progenitors give rise to two main cell lineages: pit and gland mucous cells. This study was designed to examine the changes that occur in pyloric antral mucous cell lineages and their progenitors during development of gastric adenoma and carcinoma in trefoil factor 1 (TFF1) knockout mice.

MATERIALS AND METHODS

Pyloric antral mucosal tissues of TFF1 knockout mice at ages from 3 days to 17 months were processed for histochemical analysis using Ulex europaeus and Grifforia simplifolica lectins as markers for pit and gland mucous cells, respectively. The dividing epithelial progenitors were identified by using immunohistochemical and electron microscopy techniques.

RESULTS

TFF1 loss was associated with amplification of both mucus-secreting pit and gland cells. Both lectins examined bound not only to mature mucous cells, but also to most of epithelial progenitors which gradually amplified with age and frequently were seen in mitosis. Analysis of 12- to 17-month-old TFF1-deficient stomachs revealed occasional groups of poorly differentiated mucosal cells with features similar to those of epithelial progenitors (or stem cells), in the basal portion of the antral mucosa. These cells eventually invaded the muscularis mucosa while maintaining some capacity to differentiate.

CONCLUSION

This study shows that the progenitors of pit and gland mucous cells contribute to gastric carcinogenesis in the pyloric antrum of TFF1 knockout mice, strongly supporting the concept of stem cell origin of cancer.

Fundamental physio-mitotic theory

In differentiation division, the mitosis occurring within all tissues consists of more than one type of mitosis. It occurs as two antagonistic types: the essential duplication mitosis activated by the effect of duplication factor and the antagonistic maturation mitosis which develops from the essential type and is further stimulated by maturation factor. These different types of mitosis play antagonistic roles in histological development, while maintaining a specified physio-mitotic balance through their respective mitotic factors and mitotic regulatory mechanisms in the tissues. Depending on the physio-mitotic balance between duplication and maturation mitosis, each layer of organized tissue, comprised of intrinsic functional cells, differentiates from one of the three germ layers, without errors that create abnormal characteristics. In this way, the tissues establish histological identity and continuity while maintaining a prescribed histological organization without excess or reduced multiplication within the tissues. This forms the fundamental basis of the physio-mitotic theory.

Mesoderm layer and fibrous support tissues essential for embryological differentiation

Of the three germ layers, the mesoderm layer is the first to differentiate from the blastula and continues to lead the embryological differentiation while initiating the secretion of antagonistic duplication and maturation factors. After differentiation and while maintaining the secretion of duplication and maturation factors, the fibrous tissues that differentiated from mesoderm play an essential role in regulating the physio-mitotic conditions of functional tissues found in all histological organizations. Accordingly, some defects in mitotic interaction between the fibrous and functional tissues organized into structural units may give rise to various diseases such as carcinoma, sarcoma, leukemia, and fibro-multiplastic, myo-atrophic and neuroatrophic diseases. This defect in mitosis suggests the most important step in achieving eradication of these diseases.

Cancerous genetic peculiarities non-responsible for cancer development

Certain genetic peculiarities recently identified in cancer cells have generally been regarded as the abnormalities responsible for cancer development. However, these abnormalities may also be found in maturable cancer cells and are not limited only to the non-maturable type. As previously described by the authors, cancer tissue consists of two types of cancerous cells: maturable and non-maturable. The development of cancer may be dependent only on the non-maturable cancerous stem cells, not on the maturable type. Since the non-maturable cell may be solely responsible for carcinogenesis, the relevant genetic peculiarities that are also found in the maturable cancer cells should not be regarded as the abnormalities responsible for carcinogenesis.

Physio-mitotic theory and a new concept of embryological differentiation

According to the physio-mitotic theory described previously by the authors (10,11), general mitosis consists of two different types: essential duplication and converted maturation. In general embryological differentiation, progression for the most fundamental blastocysts of the three germ layers to the immature stem cells comprising functional organic tissues is dependent on the essential duplication mitosis. This mitosis replicates stem cells while gradually initiating latent cellularities whereas the converted maturation process merely amplifies these latent cellularlities by maturing the basic cells in differentiated functional end cells with a pre-determined life span. The differentiation from the three-germ layer to embryologically organized tissues is dependent on duplication mitosis while being regulated by interactions with maturation mitosis. Thus, the complicated embryonic differentiation must be established in each type of organic tissue. During the process, these two types of mitosiseach play an antagonistic role in the embryological development of the other. This is another application of the physio-mitotic theory.

Leukemia eradication and the effect of maturation factor

As described previously (1), the development of leukemia might be attributable to the deteriorated effect of a maturation factor on the relevant type of the leukemic leukocytes, rather than a certain cellular defect initiated in the individual leukemic leukocytes. Thus, the eradication of the leukemia should depend on re-establishing the effect of the maturation factor, rather than persistent destruction of individual leukemia leukocytes. The most powerful effect of the maturation factor may be exerted throughout the mitotic duplication process of the most immature fibro-blastocysts in an in vitro cell culture. Thus, to achieve leukemia eradication, this specific cell culture, which might indefinitely be duplicating the immature fibro-blastocysts in the lineage of leukemic leukocytes, should be investigated and developed. Additionally, a technical method of extracting the maturation factor for the maturation mitosis of leukemic leukocytes should be devised and developed in the future.