(7) Third, the
de-differentiation theory indicates that existing papillary, follicular, medullary, and anaplastic thyroid carcinoma de-differentiate into SCC.
The finding is the first to show that mammalian adult stem cells can march backward along the developmental timeline in a process called
de-differentiation to become more primitive in response to environmental signals.
Evans, "
De-differentiation of papillary thyroid carcinoma into squamous cell carcinoma.
Exact origin of melanoma in GCTs is unknown but these may occur from transformation of dermal elements or
de-differentiation of germ cells to melanomas.
It occurs more commonly in the extremities, and cases of primary undifferentiated pleomorphic sarcoma of the penis are very difficult to find.[sup.9] El Hayek and colleagues[sup.10] suggest that one possible explanation could be the occurrence of
de-differentiation. On the other hand, the tumour could have been pleomorphic from the start.
GBM frequently arises de novo, but may develop from diffuse or anaplastic astrocytomas that undergo
de-differentiation. (4) Glioblastoma is the most common brain tumour, accounting for 12 - 15% of intracranial neoplasms and 50 - 60% of astrocytic tumours.
However, no experiments published have directly demonstrated this
de-differentiation process, so Li and his research team remained skeptical.
Stem cell scientists in China have used a technique known as
de-differentiation to re-engineer cells to a more primitive state that increases cell survival rates and offers greater potential for clinical use.
The unit prevents
de-differentiation of adult cardiomyocytes, encourages pre-commitment of stem cells toward certain muscle phenotypes and is suited for cardiac tissue engineering.
In particular, he discusses the definition and classification of cancer, cellular carcinogenesis as a monoclonal multi-step threshold phenomenon, the five types of genetic and molecular changes leading to cancer, causes of cancer, cellular changes associating malignant transformation or
de-differentiation, tumor recurrence and metastasis, tumor markers, natural inhibitors of the multi-stage carcinogenesis, and biochemical bases of current anti-cancer treatments.
Having learnt some lessons from SCNT (cloning), we need to be very cautious in generating stem cells by directed differentiation (IPS) or
de-differentiation for cell therapy to treat diseases.