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Mitotic cycle and cell differentiation in squamous cell carcinomas
Author(s) -
Frankfurt O. S.
Publication year - 1967
Publication title -
international journal of cancer
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.475
H-Index - 234
eISSN - 1097-0215
pISSN - 0020-7136
DOI - 10.1002/ijc.2910020405
Subject(s) - mitosis , cell cycle , cell , biology , epithelium , cell growth , cellular differentiation , cancer cell , cell division , cancer , microbiology and biotechnology , pathology , medicine , genetics , gene
The mitotic cycle and cell differentiation in the second generation of transplanted squamous cell carcinomas were studied autoradiographically with the aid of thymidine‐ 3 H. The results obtained were compared with those reported earlier on normal squamous epithelium of the mouse forestomach, from which these carcinomas originated. Proliferation in squamous cell carcinomas was significantly accelerated, mainly as a result of shortening of the G 1 phase. The rate of cell differentiation changes less significantly when measured by the duration of the maturation phase or of cell lifetimes in the differentiated state. The percentage of cells which were destined to differentiate was 17–34% out of all cells in the mitotic cycle in tumors. This value, which in a normal steady state is 50%, characterizes the extent of disturbance of balance between cell proliferation and differentiation. The most significant difference in the cell cycle for normal and tumor cells is observed in the phase at which cells that will differentiate get out of the mitotic cycle; this is the presynthetic phase for normal cells and premitotic phase for cancer cells. The significance of this qualitative difference in the life cycles of normal and cancer cells is discussed with respect to disturbance of steady state and progressive growth.