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Alteration in gene expression at the onset of hormone-dependent mammary tumor regression

F L Huang, Y S Cho-Chung

    Cancer Research
    |May 1, 1983
    PubMed

    Insights

    Hormone removal alters gene expression in mammary tumors, causing regression. Changes in specific protein production indicate genetic modification drives tumor growth and hormone dependence.

    Area of Science:

    • Oncology
    • Molecular Biology
    • Endocrinology

    Background:

    • Hormone-dependent mammary tumors regress upon hormone withdrawal.
    • The underlying mechanisms of this regression are not fully understood.

    Purpose of the Study:

    • To investigate if mammary tumor regression is triggered by changes in genetic expression.
    • To identify specific genetic alterations associated with hormone dependence.

    Main Methods:

    • Studied two hormone-dependent mammary carcinoma models (DMBA-induced and MTW9).
    • Analyzed in vitro translation products of poly(A)+ RNAs from growing and regressing tumors.
    • Compared protein profiles using electrophoresis.
    • Examined tumors with autonomous growth.

    Main Results:

    • In vitro translation products differed between growing and regressing tumors.
    • Specific protein bands (Mr 53,000, 35,000, 22,000, 20,000) decreased, while one (Mr 20,500) increased during regression.
    • These changes occurred within 6 hours of hormone removal and reversed upon hormone replenishment.
    • Autonomously growing tumors showed a distinct, stable translation pattern.

    Conclusions:

    • Hormonal regulation of mammary tumor growth involves specific genetic transcripts.
    • Changes in genetic expression correlate with hormone dependence and tumor regression.
    • Loss of hormone dependence may be linked to alterations in genetic control mechanisms.

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