Josée J. König

Gain and loss of chromosomes 1, 7, 8, 10, 18, and Y in 46 prostate cancers

Fluorescence in situ hybridization (FISH) with centromere probes was used to investigate numerical aberrations of chromosomes 1, 7, 8, 10, 18, and Y in 46 prostate carcinoma (PC) and 11 benign prostatic hyperplasia (BPH) samples. None of the benign specimens showed any chromosomal aberration. Forty-one of 46 PC specimens showed numerical aberrations of one or more chromosomes. All investigated chromosomes showed numerical aberrations in at least 30% of the specimens, gain being more frequent than loss. Comparison of DNA flow cytometry (FCM) and FISH results showed that not only aneuploid tumors but also most diploid tumors harbored numerical chromosome aberrations. Chromosome 10 was the most frequently gained (65%), and Y the most frequently lost chromosome (14%). Nonmetastatic and metastatic tumors differed significantly (P < .05) in the number of copies for chromosomes 7, 8, and 10, but not for 1, 18, and Y. These results suggest strongly that gains of chromosomes 7, 8, and 10 are involved in PC progression.

Specific cytogenetic aberrations in two novel human prostatic cell lines immortalized by human papillomavirus type 18 DNA

Using chromosome banding and fluorescence in situ hybridization (FISH) with painting probes, sequential cytogenetic analysis was performed of two novel prostate cell lines, PZ-HPV-7 and CA-HPV-10, established by human papillomavirus (HPV) 18 DNA transformation. PZ-HPV-7 originates from a normal diploid prostate epithelial cell strain. PZ-HPV-7 progressed from an initial diploid to a hypertetraploid chromosome number with a relative gain of chromosomes 5 and 20 (7 to 8 copies each). Structural changes were limited; 3p- (2 copies), 3q- (1 copy), and possibly a der(16p;12q). CA-HPV-10 originates from an epithelial cell strain derived from a high-grade human prostate cancer specimen, which showed several karyotypic abnormalities including an extra Y chromosome and double minutes (dmin). In early passage the karyotype of CA-HPV-10 appeared unstable with a decreasing number of cells exhibiting dmin. In late passage the dmin were replaced by a large homogeneously staining region (hsr) on 9p+ marker. The hsr was shown by FISH to be of chromosome 1 origin. The modal number was mainly hypertriploid (72, range 69 to 75). Loss of Y was remarkable (0 to 1 copy). Consistent markers included two copies each of del(1)(q12q31) and der(9)t(1;9)(?;p22), and one der(11)t(4;11) (?;q21). HPV type 18 genomic integration sites were identified on 1p for PZ-HPV-7 and on the 9p+ marker for CA-HPV-10. In conclusion, both PZ-HPV-7 and CA-HPV-10 showed clonal cytogenetic changes. These two cell lines constitute a novel in vitro model to study the mechanisms involved in human prostate carcino-genesis.

Prostatic Epithelium Inhibiting Factor (PEIF): Organ Specificity and Production by Prostatic Fibroblasts

SummaryThe effects of prostate fibroblast conditioned medium on two prostate epithelial cell lines (PC-3, LNCaP) and on two non-prostatic cell lines (MCF-7, K562) was investigated. As prostate fibroblast conditioned medium exerts its main effect on DNA synthesis, 3H thymidine incorporation was monitored to measure factor activity. Conditioned media of all prostatic fibroblast lines investigated were inhibitory for PC-3, LNCaP and MCF-7. Conditioned medium of prostatic fibroblasts was clearly stimulatory for K562. Prostate specificity of production of PEIF was demonstrated by the fact that conditioned medium from skin fibroblasts proved to be stimulatory for PC-3. Inhibitory activity from conditioned medium as well as from a BPH homogenate was precipitated by 33–67% ammonium sulfate. These partly purified fractions were respectively five and ten times as active as “crude” conditioned medium. The physical nature of PEIF (protein or macroglycolipid) as well as the possible function (as a signal messenger between stroma and epithelium) is discussed.

Cytogenetic Analysis of 39 Prostate Carcinomas and Evaluation of Short Term Tissue Culture Techniques

Karyotypic analysis was performed on 102 prostate cancer specimens which were obtained through radical prostatectomy, transurethral resection, or regional lymph node dissection. Short term tissue culture was applied in all cases. Of the media and growth factors evaluated, F12/DMEM, supplemented with 2% fetal calf serum, insulin, epidermal growth factor, hydrocortisone, and cholera toxin produced the largest increase of in vitro proliferation. Such in vitro cultured cells were all phenotypically acinar epithelial cells, the supposed targets for neoplastic transformation. Stromal cell growth appeared to be completely suppressed. Of the three culture techniques investigated, the method developed in Lund, Sweden, was the most successful: 11/15 cultures yielded metaphases and, in three of these, clonal aberrations were identified. All 39 karyotypes obtained essentially had a 46,XY karyotype with clonal aberrations (eight cases) and/or nonclonal aberrations (30 cases). Clonal structural aberrations involved 2p, 3q, 11p, 17p, and 21q. The clonal numerical aberrations found were: + 8, + dmin, and -Y. The most frequently observed nonclonal aberrations were 8p deletions (five cases) and loss of 6, 7, 8, 15, 17, 18, 21, and/or Y (> or = five cases). In summary, clonal aberrations were observed in 20% of the evaluable PC cell cultures, and nonclonal aberrations in 77%. So, although diploid cells without clonal abnormalities still had a growth advantage, under optimal conditions PC cells were able to proliferate in primary in vitro culture.

Cytogenetic characterization of an established xenografted prostatic adenocarcinoma cell line (PC-82)

Detailed cytogenetic analysis was performed of a xenografted human prostatic adenocarcinoma cell line PC-82. A direct preparation method was developed that yielded metaphases of good quality. Flow cytometric data and banding analysis of metaphases showed a near-tetraploid karyotype with 18 consistent marker chromosomes. As a result of the rearrangements involved, parts of chromosomes 2, 3, 4, 7, 9, 10, 15, 18, and 21 were homozygous, while regions on 2p, 13q, and 17q were apparently completely lost. In contrast to this, some regions on #2, #5, and, especially, on #1 were present in three or even four times the normal copy number. Comparison of affected chromosomes in PC-82 with all data available on prostatic carcinoma showed chromosomes 1, 2, 3, 6, 7, 10, and 15 to be involved in rearrangements in over 50% of all prostatic carcinomas. When only data from primary prostatic adenocarcinomas (including PC-82) were taken into account it appeared that chromosomes 1, 7, and 10 were involved in all five primary tumors studied.

Characterization of chromosome 8 aberrations in the prostate cancer cell line LNCaP-FGC and sublines

Abstract In two androgen-dependent (FGC and P70) and two androgen-independent (LNO and R) sublines of the prostate cancer model LNCaP numerical and structural aberrations of chromosome 8 were investigated in detail. The techniques used were whole chromosome paint (WCP) and fluorescence in situ hybridization (FISH) with three cosmid probes mapping to different parts of the p-arm (D8S7 (8p23.3), LPL (8p22) and PLAT (8p11.1)). By WCP all four cell lines showed four copies of chromosome 8 in most cells. However, FISH demonstrated that in all sublines deletions in the 8p region were present. The majority of both FGC and P70 had two copies of cosmids D8S7 and LPL. The cosmid PLAT showed a broader distribution (1–4 copies), especially in P70. Compared with FGC and P70, both LNO and R showed a larger number of copies (3 or 4) of all three cosmid loci. It is discussed that this difference is probably the result of nondisjunction as a reaction to loss of other sequences on 8p, possibly the tumor suppressor gene (TSG) mapping to 8p21. The fact that both sublines LNO and R are androgen-independent raises the possibility of a link between TSG loss on 8p and androgen independence.