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The expression of the gap junctional protein Cx43 is restricted to proliferating and non differentiated normal and transformed keratinocytes
Author(s) -
Gibson D. F. C.,
Bikle D. D.,
Harris J.,
Goldberg G. S.
Publication year - 1997
Publication title -
experimental dermatology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.108
H-Index - 96
eISSN - 1600-0625
pISSN - 0906-6705
DOI - 10.1111/j.1600-0625.1997.tb00201.x
Subject(s) - keratinocyte , cell growth , proliferation marker , microbiology and biotechnology , cell culture , cell division , gap junction , biology , cellular differentiation , cell , intracellular , gene , genetics
The passage of specific growth modulating signals through gap junctions may regulate the proliferation and differentiation of human keratinocytes. To investigate this, we correlated the proliferation of normal human keratinocytes and a transformed squamous cell carcinoma cell line, SCC4. with the expression of the gap junctional proteins Cx43. 31 and 31.1, known to be expressed by keratinocytes. Proliferation was con‐lined to preconfiuent and confluent cultures of normal keratinocytes, falling to undelectable levels once poslconfluency was achieved. Cx43. at both the message and protein levels, paralleled these changes, being elevated predominantly in prcconiluent and confluent cultures, and downregulated in postconfluency. Similar results were found for Cx31 and 31.1 at the message level. In contrast, the proliferation of SCC4 cells cultured in media supplemented with 5.0° FCS was maintained at n substantial level from preconfluency through 2 weeks postconfluency. Cx43, 31. and 31.1 RNA and Cx43 protein expression mirrored the levels of proliferation within SCC4 cultures. Cx26 and 32 were not found in normal keratinocytes or SCC4 cells at any stage of differentiation. These data, illustrating a tight correlation between proliferation and Cx43, 31 and 31.1 expression, suggest that these connexins may represent proliferation‐specific gap junctions within keratinocytes. and may therefore transmit signals that control keratinocyle division.