{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,9]],"date-time":"2026-07-09T21:47:35Z","timestamp":1783633655305,"version":"3.55.0"},"reference-count":0,"publisher":"Oxford University Press (OUP)","issue":"4","license":[{"start":{"date-parts":[[1990,4,1]],"date-time":"1990-04-01T00:00:00Z","timestamp":638928000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/academic.oup.com\/pages\/standard-publication-reuse-rights"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[1990,4,1]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:p>Retinoic acid (RA) has been shown to be required for the maintenance of epithelial differentiation. Vitamin A deficiency in hamsters induces the tracheal epithelial cells to undergo squamous metaplasia. Reversing the vitamin deficiency restores the tracheal epithelial cells to their normal morphology and function. Using a hamster tracheal epithelial (HTE) cell culture system which undergoes differentiation to predominantly secretory cells in vitro, we found that RA can convert flat, squamous-like cells to compact, cuboidal-like cells, and that it stimulated cell proliferation. The mitogenic response to RA was maximal at 10\u22127 M and required at least 48 h of treatment to observe the effect. RNA levels of growth-related genes during the growth and differentiation phases of primary HTE cultures were examined by Northern analysis. RA maintained a high level of c-myc RNA expression in preconfluent cultures, whereas untreated cells had low amounts of c-myc RNA. Expression of RNA for the replication-dependent histone 3.2 followed a similar pattern, i.e., its level was high in retinoid-treated versus control preconfluent cultures. In confluent (fully differentiated) HTE cell cultures, both retinoid-treated and control cells had low RNA levels of c-myc and histone 3.2. c-fos RNA levels were undetectable in either control or treated cells at any stage during primary culture. The RNA level of c-Ha-ras was very low in both control and treated cultures and did not vary with the state of growth or differentiation, except that when RA-treated cultures reached confluence, no c-Ha-ras RNA was detected. These results suggest that primary cultures of HTE cells are similar to fibroblasts in that increased expression of c-myc and histone is associated with the proliferative state. They also show that in addition to restoring HTE cell morphology, RA stimulates and prolongs the proliferative state of HTE cells.<\/jats:p>","DOI":"10.1165\/ajrcmb\/2.4.365","type":"journal-article","created":{"date-parts":[[2013,4,3]],"date-time":"2013-04-03T23:08:08Z","timestamp":1365030488000},"page":"365-371","source":"Crossref","is-referenced-by-count":12,"title":["The Effect of Retinoic Acid on Growth and Proto-oncogene Expression in Hamster Tracheal Epithelial Cells"],"prefix":"10.1093","volume":"2","author":[{"given":"Richard M.","family":"Niles","sequence":"first","affiliation":[{"name":"Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Barbara P.","family":"Loewy","sequence":"additional","affiliation":[{"name":"Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kate","family":"Brown","sequence":"additional","affiliation":[{"name":"Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"286","published-online":{"date-parts":[[1990,4,1]]},"container-title":["American Journal of Respiratory Cell and Molecular Biology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/academic.oup.com\/ajrcmb\/article-pdf\/2\/4\/365\/67278556\/ajrcmb_2_4_365.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/academic.oup.com\/ajrcmb\/article-pdf\/2\/4\/365\/67278556\/ajrcmb_2_4_365.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,3,18]],"date-time":"2026-03-18T09:25:43Z","timestamp":1773825943000},"score":1,"resource":{"primary":{"URL":"https:\/\/academic.oup.com\/ajrcmb\/article\/2\/4\/365\/8511919"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1990,4,1]]},"references-count":0,"journal-issue":{"issue":"4","published-online":{"date-parts":[[1990,4,1]]},"published-print":{"date-parts":[[1990,4,1]]}},"URL":"https:\/\/doi.org\/10.1165\/ajrcmb\/2.4.365","relation":{},"ISSN":["1044-1549","1535-4989"],"issn-type":[{"value":"1044-1549","type":"print"},{"value":"1535-4989","type":"electronic"}],"subject":[],"published-other":{"date-parts":[[1990,4]]},"published":{"date-parts":[[1990,4,1]]}}}