Cancer Prevention? Fundamental Genomic Alterations Are Present in Preneoplasia, Including Function of High Frequency Selected Mutations (HFSMs)

In a series of publications a special, tetraploid diplochromosomal division system to only two types of progeny cells (4n/4C/G1 and 2n/4C para-diploid) has been suggested to initiate preneoplasia that can lead to a cancerous pathway. Colorectal and other preneoplasia are known with the pathogenic, histological phases of hyperplasia to arrested adenoma/nevi that can give rise to dysplasia with high risk for cancer development. The present theme is to find solutions to tumorigenic unsolved, biological problems (queries), explainable from the tetraploid 4n-system, which would support its operation in the cancerous pathway. Presently admitted, the mutational sequencing of the cancer genome (cancer chemistry) cannot discover so-called “dark matter”, which herein is considered to be the queries. The solutions from the 4n-system were largely supported by mutated APC-induced same type of tetraploidy from the mitotic slippage process. But importantly, these behaviors and consequences could be linked to the beginning of hyperplastic lesions and their development to the arrest-phase of preneoplasia (polyps/nevi). Function of HFSMs is mostly unknown, but for Barrett’s esophagus, HFSMs (p53, p16ink4a) caused inactivation of the Rb gene, leading to dysplasia with 4n, aneuploid, abnormal cell cycles. In vitro models of the 4n-system from normal human cells recapitulated preneoplasia-like histopathological changes. It was speculated that the “cancer-crucial” step to dysplasia could be therapy-vulnerable to CRISPR-caspase editing, and perhaps antibody treatment. Additionally, the 4n-system with spontaneous cell-behaviors together with preneoplasia molecular data promises construction of a more truthful cancer-paradigm than from sequencing data alone.

Epigenetic Enabled Normal Human Cells, Lead to <i>First Cell</i>’s Unique Division System, Driving Tumorigenesis Evolution

Normal cells must become cancer-enabling before anything else occurs, according to latest literature. The goal in this mini-review is to demonstrate special tetraploidy in the enabling process. This we have shown from genomic damage, DDR (DNA Damage Response) activity with skip of mitosis leading to diploid G2 cells at the G1 border in need of chromatin repair for continued cell cycling to the special tetraploid division system. In several studies specific methylation transferase genes were activated in normal human cells in tissue fields, containing different cell growth stages of the cancerous process. Histology studies, in addition to molecular chemistry for identification of oncogenic mutational change, were a welcome change (see below). In a study on melanoma origin, DDR also showed arrested diploid cells regaining cycling from methylation transferase activity with causation of 2n melanocytes transforming to 4n melanoblasts, giving rise to epigenetic tumorigenesis enabled First Cells. Such First Cells were from Barrett’s esophagus shown to have inherited the unique division system from 4n diplochromosomal cells, first described in mouse ascites cancer cells (below). We discovered that the large nucleus prior to chromosomal division turned 90° relative to the cytoskeleton axis, and divided genome reductive to diploid, First Cells, in a perpendicular orientation to the surrounding normal cells they had originated from. This unique division system was herein shown to occur at metastasis stage, implying activity throughout the cancerous evolution. Another study showed 4-chromatid tetraploidy in development to B-cell lymphoma, and that such cancer cells also proliferated with participation of this unusual division system. Such participation has long been known from Bloom’s inherited syndrome with repair chiasmas between the four chromatids, also an in vitro observation by us. Our cytogenetic approach also revealed that they believed mitotic division in cancer cells is wrong because such cell divisions were found to be from an adaptation between amitosis and mitosis, called amitotic-mitosis. Amitosis means division without centrosomes, which has long been known from oral cancer cells, in that MOTCs (microtubule organizing center) were lacking centrioles. This observation calls for re-introduction of karyotype and cell division studies in cancer cell proliferation. It has high probability of contributing novel approaches to cancer control from screening of drugs against the amitotic-mitotic division apparatus.