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.

Octreotide combined with goserelin in the therapy of advanced pancreatic cancer--results of a pilot study and review of the literature

The two hormone analogues octreotide and goserelin have been shown to decelerate growth of human pancreatic cancer in vitro and in vivo. The objective of this pilot study was to investigate the efficacy and toxicity of the combination of these two agents in patients with advanced pancreatic cancer. Octreotide was injected subcutaneously in dosages increasing weekly, starting with 50 micrograms twice daily, until the level of maintenance therapy of 500 micrograms three times a day was reached. In addition, 3.8 mg goserelin acetate was administered subcutaneously at monthly intervals. A median of 7 cycles (range 1-27 cycles) were applied; 13 out of 14 patients entered into the study were evaluable for response and all 14 were evaluated for toxicity. In one patient with initially non-resectable pancreatic cancer, systemic therapy yielded a partial remission lasting 9 months. The degree of tumour regression then allowed a consecutive macroscopic radical tumour resection followed by an additional 6 months of no evidence of disease while the same drug combination was continued. In an additional 9 patients, no change of disease was observed, in some cases for a remarkably long time (up to 27 months). Nevertheless, the objective response rate of 7% (95% confidence interval 0 +/- 21%) was low. In 5 patients a clear improvement in their performance status was seen soon after the start of therapy; 3 patients showed progression of the disease at first evaluation or earlier and 1 patient was not evaluable at the time of study assessment. According to the product-limit method of Kaplan and Meier, the time to progression was 3.0 +/- 1.8 months [median +/- asymptotic standard error (ASE)] and overall survival was 6.0 +/- 1.5 months (median +/- ASE). Toxicity was rare and only of mild to moderate degree. Overall, the regimen under investigation did not meet the criteria for sufficient antitumoural effectiveness. Nevertheless, this study reinforces the concept that pancreatic cancer is principally responsive to endocrine therapy and therefore the further investigation of hormonal manipulation seems worth while in the future.

Involvement of heregulin-beta2 in the acquisition of the hormone-independent phenotype of breast cancer cells

The erbB-2 receptor plays an important role in the prognosis of breast cancer. Amplification or overexpression of the erbB-2 proto-oncogene has been detected in 30% of breast cancers and is associated with poor patient prognosis. The significance of erbB-3 and erbB-4 in breast cancer is not yet known. The discovery of the growth factor heregulin (HRG) has allowed us to investigate a number of biological events that are regulated by erbB-2, -3, and -4 signal transduction. To determine the role of HRG in breast cancer tumor progression, we have developed an in vitro/in vivo model. We transfected HRG cDNA into the estrogen receptor (ER)-positive breast cancer cell line, MCF-7, and studied these cells as they progressed from a hormone-dependent to -independent phenotype. The biochemical and biological characteristics presented here demonstrate that overexpression of HRG induces morphological changes in MCF-7 cells as well as erbB-2, erbB-3, and erbB-4 autophosphorylation. MCF-7/ heregulin-transfected cells, which express relatively high levels of HRG, developed estrogen independence and resistance to antiestrogens in vitro and in vivo. This is consistent with a more aggressive hormone-independent phenotype. In contrast with control parental/wild-type cells, estradiol-mediated down-regulation of erbB-2 expression is blocked completely in this particular model system. These results indicate that HRG plays a role in the disruption of ER function. When a transient transfection with an ERE-CAT construct was introduced into these HRG-transfected MCF-7 cells, we observed that the ER was transcriptionally inactive. This suggests that ER signaling is altered in HRG-transfected cells. We observed that overexpression of HRG induces a more aggressive, hormone-independent phenotype that is most likely directly related to the constitutive activation of the erbB-2, erbB-3, and erbB-4 receptor signaling cascade. The data presented here suggest a close cross-regulation between the erbB-2/4 receptors and ER and provide new insights into the mechanism by which breast cancer cells acquire a hormone-independent phenotype.

Macrophage colony-stimulating factor is expressed by an ovarian carcinoma subline and stimulates the c-myc proto-oncogene

A small, fast-growing and non-differentiated clone (N.1) derived from the heterogeneous human epithelial ovarian carcinoma cell line HOC-7 produces an autocrine/paracrine factor that is secreted into the cell culture supernatant. This factor is capable of enhancing mRNA levels of the proliferation-related oncogene c-myc in the more differentiated clone D3 and in normal human fibroblasts MRC.5, but also in N.1 cells themselves. Supernatants enriched for this paracrine/autocrine factor also confer a mitogenic stimulus as measured by [3H]thymidine incorporation. Trypsin can neutralise the stimulating activity of the secreted factor as well as monoclonal antibodies directed against macrophage colony-stimulating factor (M-CSF). We show that M-CSF and also M-CSF receptor are expressed in N.1 cells and that recombinant M-CSF induces c-myc transcript levels in N.1 cells. This investigation raises the possibility that M-CSF might be an autocrine growth factor in non-differentiated ovarian carcinomas. Inappropriate cytokine production could create a tumour-promoting microenvironment in this cancer type.

Retinoic acid induced death of ovarian carcinoma cells correlates with c-myc stimulation

In the ovarian adenocarcinoma subline N.I, all-trans retinoic acid (ATRA) induced substantial cell death. This response was elicited only at decreased serum levels. Exposure of N.I cells to increasing concentrations of ATRA was accompanied by a considerable up-regulation of c-myc transcript levels that correlated with the rate of cell killing, which itself was an active process as judged by sustained transcriptional expression. ATRA-triggered rounding and detaching of single cells from the substratum was accompanied by degradation of genomic DNA. We show that the N.I model cell line, which is otherwise highly ATRA-resistant, can undergo an ATRA-triggered suicide program when serum is limited. The accompanying c-myc up-regulation seems to be mediated by retinoic-acid-receptor-independent pathways involving membrane-associated phospholipases instead, because manoalide partly suppressed c-myc induction by ATRA but left constitutive c-myc expression unaffected.

Regulation of interleukin-8 gene expression by all-trans retinoic acid

We have studied the relationship between interleukin-8 (IL-8) and interleukin-1 alpha (IL-1 alpha) release after stimulation with all-trans retinoic acid (ATRA) and tumor necrosis factor-alpha (TNF-alpha) in the human epithelial ovarian cancer cell line HOC-7. Both IL-1 alpha and IL-8 protein release were enhanced by treatment with ATRA and TNF-alpha after 48 h exposure. Blocking of IL-1 alpha activity in HOC-7 cells with either IL-1 receptor antagonist (IL-1ra) or a neutralizing antibody directed against IL-1 alpha resulted in a dose-dependent decrease of IL-8 release by ATRA, TNF-alpha and IL-1 alpha treated HOC-7 cells. Expression of IL-8 mRNA was enhanced by the individual stimuli, whereas co-treatment with IL-1ra resulted in a loss of IL-8 specific transcripts, except in TNF-alpha treated cells. Inhibition of de novo protein synthesis by cycloheximide (CHX) and simultaneous blocking of IL-1 alpha activity by IL-1ra for 24 h revealed that ATRA controls IL-8 gene expression transcriptionally and that the extent of IL-8 protein release can be markedly influenced by cellular expressed IL-1 alpha.

In vitro and in vivo evaluation of the combination of cisplatin and its analogue carboplatin for platinum dose intensification in ovarian carcinoma

BACKGROUND

Cisplatin and its analogue carboplatin have been shown to cause dose-dependent growth inhibition throughout a wide dose range in the ovarian cancer cell lines OVCAR-3, 2780, HTB-77, and CRL-1572 tested. Cisplatin was 30 times more effective than carboplatin. The combination of both substances led to a less-than-synergistic effect, as was revealed by an isobologram in the OVCAR-3 cell line. Because of the different toxicity pattern, cisplatin and carboplatin theoretically are ideal candidates for combination chemotherapy in platinum-sensitive tumors.

METHODS

In a Phase II study, the efficacy, the toxicity profile, and the feasibility of combining both substances were assessed in 20 previously untreated patients with ovarian cancer. The regimen consisted of carboplatin (300 mg/m2) on day 1, followed by cisplatin (100 mg/m2) on day 2 every 4 weeks.

RESULTS

A total of 81 cycles were administered (median, 4 cycles; range, 1-6 cycles); four patients experienced complete remission and three experienced clinical partial remissions. Limiting toxicities were thrombocytopenia, leukopenia, and ototoxicity. The mean (+/- standard deviation [SD]) carboplatin and cisplatin dose intensities (DI) reached during the first four cycles of therapy were 58 mg/m2/week (+/- 18 mg/m2/week) and 21 mg/m2/week (+/- 7 mg/m2/week), respectively, which corresponded closely to the projected DI of 75 and 25 mg/m2/week, respectively. Based on the equivalence ratio of 4:1, the DI of carboplatin has been converted into the respective cisplatin DI, resulting in a total DI estimate. The overall DI of 37 mg/m2/week (+/- 14 mg/m2/week) was close to the projected one of 44 mg/m2/week.

CONCLUSIONS

Combining cisplatin with carboplatin was found to represent a feasible and efficacious therapeutic strategy for increasing platinum dose intensity.

Clonogenic growth in vitro: an independent biologic prognostic factor in ovarian carcinoma

A retrospective analysis was performed to investigate the prognostic value of growth in a human tumor clonogenic assay system for 84 ovarian cancer patients. A significant difference in survival probability (determined by the method of Kaplan-Meier) was found by univariate analysis between patients with ovarian carcinoma whose tumors manifested clonogenic growth (defined as growth of greater than or equal to five colonies per plate) and patients whose tumors did not grow. Clonogenic growth in vitro was associated with worse prognosis (P = .007, log-rank test). A number of generally accepted prognostic factors, International Federation of Gynecology and Obstetrics (FIGO) stage (P = .003), residual tumor mass (P less than .001), and grade (P = .011), were also of prognostic importance in our patient population. Multivariate analysis, based on the Cox regression model, identified clonogenic growth as a significant independent prognostic parameter in ovarian carcinoma (P = .031), in addition to the conventional risk factors. Estimation of survival of individual patients was best accomplished by combining the factors of residual tumor mass (P less than .05), age (P less than .01), and clonogenic growth (P less than .05) (in sequence of decreasing potential of risk).

Analysis of factors influencing clonogenic growth in vitro of cells from ovarian carcinoma patients

Clonogenic growth (defined as the formation of greater than or equal to 5 colonies per 5 x 10(5) viable nucleated cells per plate) of ovarian cancer specimens assessed in our clonogenic assay system was significantly associated with the proportion of tumor cells in the suspensions plated (N = 87; P = 0.0006), although there was no quantitative relationship with the corresponding plating efficiencies. An inverse correlation was observed between monocytes/macrophages/mesothelial cells (M) proportion and clonogenic growth (P = 0.013). These associations were most evident when only effusions were considered. Univariate analyses identified tumor cell content, M proportion and, to a lesser degree, granulocyte content as the only factors out of 12 examined to be correlated with colony formation. Multivariate analysis using a logistic regression model identified the proportion of tumor cells as the only significant factor predicting clonogenic growth in vitro (P = 0.0006). The overall accuracy of prediction for growth or non-growth was 63.2%.

[Vascularization of the cervical trachea and its clinical relevance. A scanning electron microscopy study on corrosion casts]

The angioarchitecture of the cervical trachea of the rat as a model was studied using scanning electron microscopy of vascular corrosion casts. Four different types of vascular pattern are described. 1. Supplying and draining vessels of the first order (Superior and inferior thyroid arteries, and inferior thyroid veins) situated within the peritracheal tissue at the lateral sides of the trachea. 2. The vessels arising from them, which have a horizontal course and lie within the intercartilaginous membrane (vessels of the second order). 3. The vessels of the third order branching from those of the second order, perforating the intercartilaginous membrane and again running vertically within the tracheal mucosa. 4. Vessels of the fourth order forming the capillary plexus of the tracheal mucosa, consisting of irregular (pars fibrocartilaginea) or rectangular (pars membranacea) meshes. The clinical relevance of the vascular patterns of the trachea is discussed in respect to ischemic tracheal lesions.

[Angioarchitecture of the retroauricular skin in humans. Scanning electron microscope studies of corrosion casts]

The angioarchitecture of the skin of the retroauricular area of a 25-year-old and a 55-year-old man was studied by scanning electron microscopy of vascular corrosion casts. Special attention was paid to the arrangement of the capillary bed of the stratum papillare corii. There is an average of 40 capillary loops per mm2. The diameters of the ascending loops of the capillaries range between 12.3 and 15.3 microns, of the descending ones between 19.0 and 22.9 microns, the length of the capillary loops is between 326 and 407 microns. The range of confidence is 95 percent. Three different patterns of arteriovenous anastomoses were found within the papillary and partly in the subpapillary capillary bed. The results showed no difference between the vascular beds of the two men. The scanning electron microscopy of vascular corrosion casts and its significance in the normal and pathological vascular bed is discussed.