Trail-induced apoptosis and interaction with cytotoxic agents in soft tissue sarcoma cell lines.

Five human soft tissue sarcoma (STS) cell lines (HTB-82 rhabdomyosarcoma, HTB-91 fibrosarcoma, HTB-92 liposarcoma, HTB-93 synovial sarcoma and HTB-94 chondrosarcoma) were analysed for their sensitivity to tumour necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) and the function of the TRAIL apoptotic pathway in these cells. TRAIL induced significant apoptosis (>90%) in HTB-92 and HTB-93 cells, whereas no effect was observed in HTB-82, HTB-91 and HTB-94 cells. TRAIL-Receptor 1 (TRAIL-R1) was expressed in TRAIL-sensitive HTB-92 and HTB-93 cell lines, but not in TRAIL-resistant HTB-91 and HTB-94 cells. HTB-82 cells, which expressed the long (c-FLIP(L)) and short (c-FLIP(S)) splice variants of the FLICE-like inhibitory protein (FLIP), were resistant to TRAIL in spite of the presence of TRAIL-R1. TRAIL-R2,-R3,-R4 and osteoprotegerin (OPG) expression did not correlate with TRAIL sensitivity. Coincubation of TRAIL and doxorubicin led to the overexpression of TRAIL-R2 resulting in a synergistic effect of doxorubicin and TRAIL in TRAIL-sensitive cell lines and in the overcoming of TRAIL-resistance in all of the TRAIL-resistant cell lines, except HTB-91, which lacked caspase 8 expression. These data suggest that TRAIL, either as a single agent or in combination with cytotoxic agents, might represent a new treatment option for advanced STS, which constitutes a largely chemotherapy-resistant disease.

High frequency of allelic imbalance at regions of chromosome arm 8p in ovarian carcinoma.

Progressive genetic changes such as the inactivation of tumor suppressor genes (TSG) are thought to play an important role in the initiation and progression of ovarian cancer. Frequent nonrandom allelic imbalance (AI) at 8p11-p21 and 8p22-pter suggests the existence of TSGs that may be involved in the carcinogenesis of several human malignancies. We investigated 70 ovarian tumors with 11 highly polymorphic markers spanning 8p12-p21 and 8p22-pter to produce an AI map of 8p in epithelial ovarian cancer. Allelic imbalance was demonstrated in 54 tumors (77%), most frequently occurring at D8S136 (54%) and at D8S1992 (55%). Poorly differentiated and advanced stage cancers were more often affected by AI (G1+G2 vs. G3; 20% vs. 66%; stage I+II vs. III+IV, 36% vs. 54%, P<.001; Kruskal-Wallis test) than well differentiated and early stage tumors. There was no relationship between histological subtype and AI. Smallest regions of overlap (SRO) were delineated by analyzing 38 tumors with partial AI. This study provides compelling evidence for the involvement of TSGs on the short arm of chromosome 8, at 8p12-p21 and at 8p23 in the development and progression of epithelial ovarian cancer.

Adenovirus E1A does not induce the Ewing tumor-associated gene fusion EWS-FLI1.

Rearrangement of the EWS gene with FLI1 is thought to occur early in the pathogenesis of Ewing's sarcoma family tumors (EFTs) because the chromosomal aberration is pathognomonic for this disease. Recently, adenovirus (Ad) 5 E1A protein has been reported to induce this gene rearrangement in a variety of cell types. This finding, if generally substantiated, not only suggests an etiological role for viral agents in the generation of oncogenic chromosomal aberrations but would also significantly impact the use of adenoviral vectors for gene therapy. In contrast, we now report on the absence of EWS-FLI1 chimeric products from short- and long-term cultures of stably Ad-transformed cells lines and from transiently E1A-expressing cell lines. In addition, we demonstrate the absence of E1A from EFTs. We conclude that there is no role for Ads in EFT pathogenesis. Consequently, evidence for a viral genesis of tumor-specific gene rearrangements is not available.

Exon trapping and sequence-based methods of gene finding in transcript mapping of human 4p16.3.

We have applied exon amplification, GRAIL2 exon prediction and EST database searching to a 2 Mb segment of chromosome 4p16.3. Experimental and computational methods of identifying exons were comparable in efficiency and apparent false positive rate, but were complementary in gene identification, revealing distinct overlapping sets of expressed sequences. EST searching was most powerful when we considered only those ESTs that show evidence of splicing relative to the genomic sequence. The combination of the three gene finding methods produced a transcription map of 30 loci in this segment of 4p16.3 that includes known human genes, homologs of loci identified in rodents and several anonymous transcripts, including a putative novel DNA polymerase and a gene related to Drosophila ash1. While most of the genes in the region have been found, our data suggest that even with the entire DNA sequence available, complete saturation of the transcript map will require additional, focused experimental effort.

Measuring extracellular matrix turnover in the serum of patients with idiopathic or ischemic dilated cardiomyopathy and impact on diagnosis and prognosis.

Circulating levels of extracellular matrix components were measured by radioimmunoassays and tested if they were useful for clinical staging in chronic heart failure. In 41 patients with dilated cardiomyopathy (33 idiopathic and 8 ischemic cases), the serum concentrations of procollagen type III aminoterminal peptide (PIIINP), type I collagen telopeptide (ICTP), and basement membrane laminin were significantly higher than in 30 healthy controls regardless of the underlying etiology. Patients with serum values of PIIINP, ICTP, and laminin > 7 micrograms/L, 7.6 micrograms/L, and 2.3 U/ml, respectively, were at higher relative risk for advanced clinical stage, poor hemodynamic condition, hyponatremia, heart transplantation, and death during follow-up than patients with low levels, with the exception that serum laminin > 2.3 U/ml was not significantly associated with hyponatremia and heart transplantation. Despite their interdependence on liver function, circulating levels of PIIINP and ICTP were independent predictors of mortality. In 17 of the 41 patients with cardiomyopathy whose explanted hearts were available for histologic evaluation, serum PIIINP, ICTP, and laminin significantly correlated with the myocardial area fractions of their tissue analogues (PIIINP vs myocardial collagen type III, r = 0.784, p = 0.0013; serum ICTP vs myocardial collagen type I, r = 0.603, p = 0.0527; and serum laminin vs myocardial laminin, r = 0.605, p = 0.0411). In conclusion, the increase in extracellular matrix turnover, which may partially be derived from fibrosis in the myocardium, can be measured in the serum of patients with dilated cardiomyopathy, and has an impact on risk stratification and prognosis.