Amplification, rearrangement, and elevated expression of c-myc in the human prostatic carcinoma cell line LNCaP.
We have investigated the structure and expression of the c-myc proto-oncogene in DNA isolated from the immortal cell line LNCaP. This cell line was derived from a lymph node metastasis of human prostate cancer. Msp I digest of LNCaP DNA when hybridized to a human c-myc probe showed a 1.45 kb band of intensity about two-fold greater than that observed in normal lymphocytes. In addition, the LNCaP cells contain rearranged and amplified c-myc structures which are not present in normal lymphocytes. Quantitation of these bands by scanning densitometry is consistent with an approximately 10-fold amplification of c-myc. To determine whether this amplification was accompanied by increased expression, RNA was isolated from these cells and compared to RNA isolated from a control cell line in which c-myc was not amplified. Northern blot analysis showed that the RNA transcripts from LNCaP cells were approximately 50-fold higher. Although androgens modulate the cell growth of LNCaP, there was no change in the level of c-myc RNA transcripts in serum-free medium in the presence or absence of androgens. Further investigation to determine whether altered structure, amplification, and overexpression of c-myc constitute a common characteristic of metastatic human prostate cancer might prove profitable in understanding this disease.
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Scott Department of Urology, Baylor College of Medicine, Houston, Texas.
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D004273:DNA, Neoplasm / Q000235:genetics; D005784:Gene Amplification; D015870:Gene Expression; D015321:Gene Rearrangement; D006801:Humans; D015151:Immunoblotting; D008297:Male; D009154:Mutation; D009857:Oncogenes; D011471:Prostatic Neoplasms / Q000235:genetics*; D000090063:Proto-Oncogene Mas; D011518:Proto-Oncogene Proteins / Q000235:genetics; D016271:Proto-Oncogene Proteins c-myc; D016283:Proto-Oncogene Proteins p21(ras); D011519:Proto-Oncogenes; D013739:Testosterone / Q000494:pharmacology; D014407:Tumor Cells, Cultured
D004273:DNA, Neoplasm; C000715470:MAS1 protein, human; D000090063:Proto-Oncogene Mas; D011518:Proto-Oncogene Proteins; D016271:Proto-Oncogene Proteins c-myc; D013739:Testosterone; C501009:HRAS protein, human; D016283:Proto-Oncogene Proteins p21(ras)