In vivo growth regulation by cytokine in breast cancer cells showing an estradiol-inhibitive response in vitro

The rates of the stimulative, insensitive, and inhibitive responses to 10(-2) nM E-2 in sixty clinical breast cancer cases were 24.2%, 45.2%, and 30.6% respectively. We then examined the expression of mRNAs of such cytokines as TNF-alpha, TGF-alpha, EGF, and TGF-beta; in cancer tissue specimens from these three different groups. In MCF-7 showing an E-2-stimulative response the expression of mRNAs of both TNF-alpha and TGF-alpha were suppressed by 10(-2) nM E-2, but these same expressions in KSE-1 showing an E-2 stimulative response were enhanced by E-2. The mRNA expression of TGF-beta in these two cell lines was suppressed by 10(-2) nM E-2, but that of EGF was enhanced. In clinical cases showing an E-2-inhibitive response, the mRNA expression ratio of TNF-alpha/TGF-beta was above 2.5, but under 2.5 in E-2-uninhibitive response cases. The mRNA expression ratio of TGF-alpha/TGF-beta was over 1.8 in the E-2-inhibitive responsive cases, brit under 1.8 in the E-2-uninhibitive response cases. The mRNA expression ratio Of EGF/TGF-beta did not show any regular tendency in three groups showing a different E-2-response in vitro. Based on in vitro results and mRNA expression in clinical cases, the cytokine expression for E-2-inhibitive cancer cells differed from those of E-2-stimulative and -insensitive cells. Therefore, E-2-inhibitive cancer cells are thus considered to possibly possess a characteristic growth regulation which is different from that for E-2-uninhibitive cancel cells.