An anti-apoptotic pattern correlates with multidrug resistance in acute myeloid leukemia patients: a comparative study of active caspase-3, cleaved PARPs, Bcl-2, Survivin and MDR1 gene.

Bone marrow samples of 17 acute myeloid leukemia (AML) patients were analyzed for apoptosis-related markers. The levels of active caspase-3 (aC-3), Bcl-2 and cleaved poly(ADP-ribose) polymerase (cPARP) were measured by flow cytometry and compared with survivin and MDR1 gene expression as defined by reverse transcriptase polymerase chain reaction (RT-PCR). The results showed heterogeneous patterns of intracellular levels of the studied proteins in AML patients: aC-3 (mean 34.6+/-52.5 U/ml), Bcl-2 (mean 3268.4+/-2055.2 U/ml), and cPARPs (mean 24.59+/-29.97 U/ml). Survivin and MDR1 genes were overexpressed in 9 and 10 patients, respectively. Patients with high levels of survivin mRNA showed significantly lower cPARPs (11.8+/-14.3 versus 53.9+/-31.9 U/ml P=0.005) and a tendency towards higher aC-3 (49.3+/-70.0 versus 18.1+/-9.9 U/ml), and MDR1 overexpression (7/9 patients versus 3/8 patients), as well as poorer therapeutic response and survival. Our data support the potential relevance of apoptosis-related markers in AML for further understanding the disease; however, the heterogeneity and complexity of molecular interactions warrants further prospective studies.

Establishment and characterization of a new human prostatic cancer cell line: DuCaP.

BACKGROUND: The lack of appropriate, clinically relevant, cell-based model systems has limited prostate cancer research and the development of new therapeutic modalities. Here we report the isolation and characterization of a new adherent prostate cancer cell line, derived from the dura mater of a cancer patient. METHODS: Prostate cancer tissue was harvested at autopsy from a metastatic lesion to the dura mater of a patient with hormone refractory prostate cancer. This tissue was xenografted into SCID mice and later harvested and plated on tissue culture dishes. For characterization, soft agar clonegenic assay, in vivo xenograft growth, in vitro doubling time, karyotype analysis, immunocytochemistry for cytokeratin-18, androgen receptor, and PAP (prostatic acid phosphatase) expression, RT PCR for PAP, PSMA (prostate specific membrane antigen), expression and northern and western blot analysis to determine expression of Rb and p53, were performed. RESULTS: DuCap grows in vitro (passage 55), forms colonies in soft agar, produces tumors in SCID mice (xenograft passage 12), and is androgen sensitive. DNA content was hypertriploid. PSA was detected in mouse serum and media. Cells were AR, PAP and cytokeratin-18 positive by immunocytochemistry. PSMA and PAP were detected by RT-PCR. AR, P53, and Rb were expressed in Northern blot analysis. P53 protein was detected in Western blot analysis but Rb protein was not. CONCLUSIONS: This cell line exhibits many phenotypic characteristics of clinical prostate carcinoma, including expression of PSA, PSMA, PAP and AR.

A globally disseminated M1 subclone of group A streptococci differs from other subclones by 70 kilobases of prophage DNA and capacity for high-frequency intracellular invasion.

The M1inv+ subclone of M1 group A streptococci that spread globally in the late 1980s and early 1990s was previously identified by restriction fragment length polymorphism (RFLP), M protein, and SpeA exotoxin sequence analyses. Strains representing this subclone were characterized with regard to carriage of bacteriophage and capacity to invade cultured human epithelial cells. The M1inv+ subclone was found to harbor two entirely different prophages, phage T13 and phage T14, which together supplement its genome with nearly 70 kb of DNA. Phage T14 encodes the SpeA exotoxin and is closely related to the classic converting phage T12. Plaque-forming characteristics and RFLP analyses of phages T13 and T14 were compared to each other and to phage T12. Other subclones of M1, isolated in the 1970s to the early 1980s, lacked both prophages. The M1inv+ subclone was previously reported to be efficiently internalized by human epithelial cells. This potential was confirmed and expanded by comparing a variety of clinical isolates. The capacity for high-frequency invasion of epithelial cells was not transmitted to a laboratory strain of group A streptococci by the above-mentioned bacteriophages.

Acute changes of alpha-fetoprotein and human chorionic gonadotropin during induction chemotherapy of germ cell tumors.

Thirty-seven consecutive patients with germ cell cancers (34 testicular, three extragonadal) and elevated serum levels of alpha-fetoprotein (AFP) and/or human chorionic gonadotropin (HCG) were treated with vinblastine, bleomycin, and cis-diamminedichloroplatinum induction chemotherapy. The AFP and/or HCG normalized in 36 patients. The AFP half-life was 7.9 days between Days 1 and 21 postchemotherapy but 6.0 days between Days 21 and 42 (p less than 0.05). The prolonged AFP half-life between Days 1 and 21 was related to a median increase of 57.5% (range, 22 to 219%) in the AFP level. This increase in the marker value occurred between Days 2 and 9 of therapy (median, Day 5). There was also a median increase of 181% (range, 27 to 600%) in the HCG level at a median of 5 days after the start of therapy. The increase in the AFP and HCG levels occurred in 63 and 70% of evaluable patients, respectively, and correlated with the presence of a large volume of metastatic disease (chi 2 = 8.87). Patients with relapsed or refractory disease had prolongation of the AFP half-life between Days 21 and 42 as compared to nonrelapsed patients. AFP and HCG half-life calculations should be used in the management of patients with germ cell cancers.