Holger Hirte

Transforming growth factor β1 acts as an inducer of matrix metalloproteinase expression and activity in human bone-metastasizing cancer cells

Bone metastases are a common complication in prostate and breast cancer patients. It leads to extensive morbidity and eventually mortality. Matrix metalloproteinases (MMPs) are known to be involved in the metastatic process. MMP activity can be down-regulated by transforming growth factor β1 (TGF-β1), a growth-modulating factor, found in high concentrations in the bone. TGF-β1 acts through the TGF-β1 inhibitory element (TIE) element, a cis-acting element found in the promoter region of most MMP genes, with the exception of MMP-2. We used three human cell lines relevant for bone metastases, namely prostate adenocarcinoma PC-3, breast adenocarcinoma MDA-MB-231, and adenocarcinoma cells of unknown origin, Hs696, and one human osteosarcoma cell line, SAOS-2, and showed that in these cell lines TGF-β1 partially lost its repressing action on MMP expression. TGF-β1 was able to induce MMP-9 activity and protein expression in all three bone-metastatic tumour cell types, whereas MMP-9 protein levels were repressed in SAOS-2 cells. In PC-3 cells, TGF-β1 repressed MMP-1 expression, whereas in MDA-MB-231 and SAOS-2 cells, an increase in the expression of MMP-1 protein was detected. Additionally, an increase in MMP-3 expression was observed in Hs696 cells. Expression and activity of the tissue inhibitors of matrix metalloproteinases, TIMP-1 and TIMP-2, were found increased in both PC-3 and MDA-MB-231 cells. With respect to cell proliferation, TGF-β1 was able to induce a dose-dependent growth inhibition of up to 50% in primary human mammary epithelial cells. However, in none of the tumour cell lines was TGF-β1 able to suppress growth substantially. Data presented in this paper support the hypothesis that TGF-β1 can potentially disrupt the balance existing between osteoclast- and osteoblast-derived MMP activity by inducing altered expression of matrix metalloproteinases and their tissue inhibitors derived from bone-metastasizing cancer cells. This could eventually lead to skeletal destruction in patients with advanced metastatic disease.

Reversal of suppression of lymphokine-activated killer cells by transforming growth factor-β in ovarian carcinoma ascitic fluid requires interleukin-2 combined with anti-CD3 antibody

Ascitic fluid from human ovarian carcinoma (AF) has been shown to inhibit IL-2-induced lymphokine-activated killer (LAK) cell generation from peripheral blood mononuclear cells (PBMC) resulting from the presence of biologically active transforming growth factor-beta (TGF-beta). A 50% concentration of AF completely suppressed the LAK response to 100 units IL-2/ml and only partial reversal (less than 50%) could be achieved by increasing the IL-2 concentration to 1000 units/ml. We evaluated the ability of tumor necrosis factor-alpha (TNF-alpha, 1-1000 ng/ml) and anti-CD3 antibody (alpha-CD3, 1-100 ng/ml) to reverse AF-mediated suppression of IL-2-stimulated LAK generation. TNF-alpha alone did not generate significant LAK activity, but in the presence of suboptimal concentrations of IL-2 (10 and 100 units/ml), TNF-alpha significantly boosted the generation of LAK, but was unable to significantly reverse AF-mediated suppression of the IL-2 response (even at 1000 units/ml). In contrast, alpha-CD3 alone generated LAK activity at concentrations as low as 1 ng/ml and markedly enhanced generation of LAK activity when added to suboptimal concentrations of IL-2. alpha-CD3 combined with IL-2 significantly reversed AF suppression at 100 units IL-2/ml and at 1000 units/ml completely reversed suppression by two of three highly suppressive samples of AF. Significant reversal occurred with the third AF sample. It may be possible to overcome TGF-beta-mediated suppression by measures other than by increasing the IL-2 concentration.

Novel strategies for systemic treatment of endometrial cancer

The median survival of women with advanced or recurrent endometrial cancer is less than one year. Of the women with early stage endometrial cancer and poor prognostic factors like high grade or deep myometrial invasion, 40% will recur. Over the last decade, incredible strides have been taken in evaluating systemic therapy for this disease, however, survival rates remain poor. Progestin therapy offers a 10 - 20% response rate and survival of less than one year. Progestins are most effective in women with well-differentiated tumours and long disease-free interval. There is no role for adjuvant progestin therapy in early stage disease. Single-agent chemotherapy with most activity include ifosfamide, cisplatin/carboplatin, doxorubicin and paclitaxel. Combination chemotherapy provides a response rate of 40 - 60%, however, median survival is still less than a year. New areas of research include the identification and evaluation of new active endocrine therapies (i.e., LY-353381.HCl and letrozole), chemotherapeutics (i.e., paclitaxel), evaluating chemotherapeutic agents in combination (i.e., paclitaxel, doxorubicin and platinum), in addition to radiation or instead of radiation. New avenues under development involve the specific molecules and pathways responsible for the initiation and growth of endometrial carcinoma (i.e., Herceptin™). Exciting developments in the understanding of the molecules involved in tumour development and metastasis will allow the development of specific and selective inhibitors.

Fractionated stereotactic radiosurgery with concurrent temozolomide chemotherapy for locally recurrent glioblastoma multiforme: a prospective cohort study.

Local recurrence represents a significant challenge in the management of patients with glioblastoma multiforme. Salvage treatment options are limited by lack of clinical efficacy. Recent studies have demonstrated a significant response rate and acceptable toxicity with the use of fractionated stereotactic radiosurgery in this patient population. Our primary objective was to determine the efficacy and toxicity of fractionated stereotactic radiosurgery combined with concurrent temozolomide chemotherapy as a salvage treatment for recurrent glioblastoma multiforme. We prospectively collected treatment and outcome data for patients having fractionated stereotactic radiosurgery for locally recurrent glioblastoma multiforme after radical radiotherapy. Eligible patients had a maximum recurrence diameter of 60 mm without causing significant mass effect. The gross tumor volume was defined as the enhancing lesion on an enhanced fine-slice T1 (spin–lattice) magnetic resonance imaging, and a circumferential setup margin of 1 mm was used to define the planning target volume. All patients were treated using robotic radiosurgery with three dose/fractionation schedules ranging from 25 to 35 Gy in five fractions, depending on the maximum tumor diameter. Concurrent temozolomide 75 mg/m2 was prescribed to all patients. Tumor response was judged using the Macdonald criteria, and toxicity was assessed using the CTCAE (Common Terminology Criteria for Adverse Events). A total of 31 patients were enrolled in this study. The median overall survival was 9 months, and progression-free survival was 7 months. The 6-month progression-free survival was 60% with a 95% confidence interval of 43%–77%. The a priori stratification factor of small tumor diameter was shown to predict overall survival, while time to recurrence was not predictive of progression-free or overall survival. Three patients experienced grade 3 acute toxicity that responded to increased steroid dosing. One patient experienced a grade 4 acute toxicity that did not respond to increased steroids but did respond to anti-angiogenic therapy. Fractionated stereotactic radiosurgery with concurrent temozolomide has shown good short-term clinical and radiologic control with manageable acute toxicity. This regimen appears to provide superior efficacy to either temozolomide or fractionated radiosurgery alone. The results of this study support the continued evaluation of this regimen.

A rapid and simple method for the purification of tumor cells from ascitic fluid of ovarian carcinoma

Rapid isolation of tumor cells growing in clumps from the ascitic fluid of patients with ovarian carcinoma was achieved by harvesting cells from ascitic fluid and subsequently passing them over a 30-microns nylon mesh filter. Single cells and small cell aggregates passed through the mesh, and large cell clumps that had not passed through the filter were isolated by backwashing. Morphologically, the cells in the clumps consisted almost entirely of tumor cells. The clumps were analyzed by immunocytochemistry and only a small proportion of cells (3.1 +/- 0.5% to 8.3 +/- 0.8%) stained with anti-CD45 monoclonal antibody (a panleukocyte marker for cells of hematopoietic origin). Most of the cells in clumps stained positively (90.6 +/- 1.7% to 97.5 +/- 0.5%) with 2G3 (a monoclonal antibody binding to a high-molecular-weight carcinoma-associated antigen). Unfiltered cell populations, however, contained up to 34.4 +/- 2.1% contaminating CD45+ non-tumor cells. This method should be useful for rapidly and easily obtained highly enriched fresh ovarian carcinoma cells from ascitic fluid in a form in which they grow naturally.

Palliative systemic therapy for women with recurrent epithelial ovarian cancer: current options

Objectives To review the available systemic treatments for women with recurrent ovarian cancer. Methods A literature review was conducted for recurrent ovarian cancer articles in English, including randomized trials, Phase II trials, or reviews. Results We discuss the efficacy and toxicity outcomes associated with systemic therapy for platinum-sensitive and platinum-resistant ovarian cancer. Clearly, platinum-based combination systemic therapy shows a prolonged progression-free interval compared with single-agent chemotherapy with a low toxicity profile. No clear superior management strategy exists for platinum-resistant/refractory disease. Novel targeted antiangiogenic agents (eg, bevacizumab), angiopoeitin inhibitors (eg, AMG 386), and poly ADP ribose polymerase inhibitors (eg, olaparib) are reviewed. Conclusion Although combination platinum-based chemotherapy has shown benefits for women with platinum-sensitive recurrent ovarian cancer, the optimal treatment strategy for those with platinum-resistant or platinum-refractory disease is not clear. Molecular and genetic targeted therapies may provide opportunities for those women with tumor profiles that show sensitivity for specific agents.

Quantification of matrix metalloproteinase activity in plasma of patients enrolled in a BAY 12-9566 phase I study

The expression of matrix metalloproteinases (MMPs) is often associated with invasiveness or grade of tumours. Increased blood levels of MMP proteins, including MMP‐1, MMP‐2, MMP‐3 and MMP‐9 have been detected in various types of cancers. With the exception of one study, MMPs in serum and plasma have been determined using ELISA. In the present study we measured the activity of the MMPs found in human plasma samples using gelatin enzymography and fluorimetric degradation assays. We used plasma samples from healthy control subjects and cancer patients enrolled in a dose‐finding study for the MMP inhibitor, BAY 12‐9566, to assess the activity of MMPs found in plasma and screen for efficacy of the MMP inhibitor. BAY 12‐9566 has inhibitory activity toward MMP‐2, MMP‐3 and MMP‐9. Patients with advanced solid tumours were enrolled in our study and plasma was collected on day 1 before dosing and at steady‐state of the drug on day 15. Our results show that BAY 12‐9566 was effective in lowering the plasma gelatinolytic activity in the group of 29 patients when considering the data obtained from a fluorimetric gelatinase assay. The data obtained from gelatin enzymography, however, did not reach significance. The fluorimetric degradation assay could be a useful tool to screen plasma from cancer patients in other clinical trials assessing MMP inhibitors.