Pia Vihinen

Matrix Metalloproteinases as Therapeutic Targets in Cancer

Degradation of extracellular matrix is crucial for malignant tumor growth, invasion, metastasis and angiogenesis. Matrix metalloproteinases (MMPs) are a family of zinc-dependent neutral endopeptidases collectively capable of degrading essentially all matrix components. Elevated levels of distinct MMPs can be detected in tumor tissue or serum of patients with advanced cancer, and their role as prognostic indicators in cancer has been widely examined. In addition, therapeutic intervention in tumor growth and invasion based on inhibition of MMP activity is under intensive investigation and several MMP inhibitors (MMPIs) are in clinical cancer trials. Even though results of the first clinical trials in advanced cancer have been mostly disappointing, there are also positive results. Recent observations show, that certain MMPs limit tumor growth. Therefore, identification of proper MMPs for therapeutic intervention with array-based molecular classifications of tumors and targeting these with more specific MMPIs in combination with conventional chemotherapy is expected to provide a feasible approach for cancer therapy. MMPIs represent a totally different therapeutic modality from proven anti-cancer drugs and thus traditional approaches to evaluate drug efficiency cannot be used without modification. In this review, we discuss the current view on the feasibility of MMPs as targets for therapeutic intervention in cancer.

High Serum Levels of Matrix Metalloproteinase-9 and Matrix Metalloproteinase-1 Are Associated with Rapid Progression in Patients with Metastatic Melanoma

Purpose: Matrix metalloproteinases (MMP) are proteolytic enzymes that play an important role in various aspects of cancer progression. In the present work, we have studied the prognostic significance of serum levels of gelatinase B (MMP-9), collagenase-1 (MMP-1), and collagenase-3 (MMP-13) in patients with advanced melanoma. Experimental Design: Total pretreatment serum levels of MMP-9 in 71 patients and MMP-1 and MMP-13 in 48 patients were determined by an assay system based on ELISA. Total MMP levels were also assessed in eight healthy controls. The active and latent forms of MMPs were defined by using Western blot analysis and gelatin zymography. Results: Patients with high serum levels of MMP-9 (≥376.6 ng/mL; n = 19) had significantly poorer overall survival (OS) than patients with lower serum MMP-9 levels (n = 52; median OS, 29.1 versus 45.2 months; P = 0.033). High MMP-9 levels were also associated with visceral or bone metastasis (P = 0.027), elevated serum alkaline phosphatase level (P = 0.0009), and presence of liver metastases (P = 0.032). Serum levels of MMP-1 and MMP-13 did not correlate with OS. MMP-1 and MMP-9 were found mainly in latent forms in serum, whereas the majority of MMP-13 in serum was active (48 kDa) form. MMP-13 was found more often in active form in patients (mean, 99% of the total MMP-13 level) than in controls (mean, 84% of the total MMP-13 level; P < 0.0001). After initiating the therapy, patients with elevated levels of MMP-1 (≥29.8 ng/mL, n = 10) progressed more rapidly than patients with lower levels (median, 1.9 versus 3.5 months; P = 0.023). Serum levels of MMP-9 and MMP-13 did not correlate with the time to progression (TTP). In multivariate analysis with age and gender, MMP-9 or MMP-1 turned out to be independent prognostic factors for OS [P = 0.039; hazard ratio (HR), 1.8; 95% confidence interval (95% CI), 1.03-3.3] or TTP (P = 0.023; HR, 2.7; 95% CI, 1.15-6.4), respectively. Conclusions: Our findings provide evidence that MMP-1, MMP-9, and MMP-13 play important roles at different phases of metastatic melanoma spread and that serum MMP-9, in particular, could have clinical value in identifying patients at high risk for melanoma progression.

Integrin chains beta1 and alphav as prognostic factors in human metastatic melanoma.

The expression pattern of integrin-type cell adhesion receptors is often changed during malignant transformation. In the present work, we studied the prognostic significance of beta1 and alphav integrin chains for survival of patients with metastatic melanoma. The expression levels of beta1 integrin were also compared with those of Bcl-2, an anti-apoptotic protein, the presence of which is associated with treatment response and survival in melanoma. The expression of beta1 and alphav integrins in 68 melanoma metastases obtained from 55 patients treated with combined chemoimmunotherapy was studied by immunohistochemistry using anti-beta1 and anti-alphav antibodies. The patients were divided into two groups (using a cut-off point of >/= 81%) for beta1 integrin expression levels and into three categories (negative/low, median, high) for alphav integrin expression levels. All tumours were positive for beta1 integrin, and the tumours (n = 6) which had the highest alphav score were also strongly positive for beta1 (94%; P = 0.0055). Patients (n = 43) with 80% or less beta1 integrin-positive tumour cells in their samples had a median disease-free survival (DFS) of 17.0 months, and patients (n = 12) with 81% or more beta1 integrin-positive tumour cells had a DFS of only 5.7 months (P = 0.0001). Patients (n = 32) with low alphav integrin expression levels had shorter DFS (median 12.3 months; P = 0.0146) than patients (n = 20) with median expression levels (median 16.7 months; P = 0.0146). However, three patients who had a very strong alphav expression in their tumours had a median DFS of only 1.8 months (P = 0.0146). Median level expression of beta1 integrin was associated with the presence of Bcl-2 in tumour cells (P = 0.0033). Our results suggest that beta1 and alphav integrin chains are independently expressed in metastatic melanoma and may have an effect on the metastatic potential of melanoma cells.

Association between high collagenase‐3 expression levels and poor prognosis in patients with head and neck cancer

Squamous cell carcinoma of the head and neck (HNSCC) is a common cancer type. The ability for curative treatment with surgery and radiotherapy (RT) is usually highly dependent on tumor stage at the time of diagnosis.

A phase Ii trial of bevacizumab with dacarbazine and daily low-dose interferon-α2a as first line treatment in metastatic melanoma

Metastatic melanomas are hypervascular tumours with poor prognosis. We hypothesized that treatment of metastatic melanoma with a combination of bevacizumab, a monoclonal antibody against vascular endothelial growth factor, dacarbazine (DTIC) and low-dose interferon α-2a (IFN-α2a) might lead to a synergistic inhibition of angiogenesis and regression of tumours. Patients with metastatic melanoma were treated with bevacizumab (5 mg/kg every 2 weeks), DTIC (200 mg/m2 days 1–5 every 4 weeks) and IFN-α2a (three MIU subcutaneously daily from day 15 onwards). Patients exhibiting response or stable disease after 6 months were treated with bevacizumab±IFN-α2a until disease progression. The primary study objectives were progression-free survival (PFS), overall survival and safety. Twenty-six patients were accrued. Response rate was 23% (two complete responses, four partial responses), and six patients showed stable disease. The median PFS for all patients was 2.3 months and for responders 8.1 months. The median overall survival for all patients was 11.5 months. Four life-threatening adverse events were seen: two pulmonary thromboembolisms, an intracerebral haemorrhage, and one grade 4 hypertension. One of the pulmonary emboli and the intracerebral haemorrhage were observed ≥3 months after the last bevacizumab–DTIC dose. Serum matrix metalloproteinase-9 and vascular endothelial growth factor levels changed during therapy. There was a trend towards favourable PFS among patients with only minimal or moderate change in these marker expression levels. The present regimen was active in this patient group but was also associated with remarkable vascular events.

Serum matrix metalloproteinase-8 is associated with ulceration and vascular invasion of malignant melanoma.

Serological markers of malignant melanoma have failed to provide prognostic significance in patients who are tumour-free after surgery. Immune response regulation is important regarding progression and therapeutic interventions of malignant melanoma. Matrix metalloproteinase (MMP)-8 is one of the collagenases involved in the regulation of tissue remodelling and immune response, being incompletely studied in melanoma as yet. We assessed whether serum MMP-8 is of prognostic value in malignant melanoma. We studied serum samples of 117 patients, of which 63 were stage I, 13 stage II, 12 stage III and 29 stage IV. The mean serum MMP-8 levels (47.5 ng/ml) did not significantly correlate with patient or tumour characteristics, that is, patient sex, age, tumour Clarks or Breslows classification, sentinel lymph node status or to survival. Importantly, high serum MMP-8 levels were significantly related to presence of vascular invasion (P=0.001) in primary tumour, tumour ulceration (P=0.003) and tumour bleeding (P=0.033). Tendency to increased serum MMP-8 levels in patients with coronary heart disease or type II diabetes mellitus was detected. These data imply that high serum MMP-8 level is associated with earlier recognized histopathology markers of melanoma progression. Results also suggest that elevated serum MMP-8 might be related to haematogenous spreading of melanoma through vascular invasion.

Serum VEGF-C is associated with metastatic site in patients with malignant melanoma

Vascular endothelial growth factor-C (VEGF-C) is involved in lymphatic metastatic spread. Metastatic site is a prognostic factor in melanoma. We assessed whether serum levels of VEGF-C are associated with metastatic sites or prognosis in patients treated for stage IV melanoma. The study included 64 patients, who received dacarbazine or four-drug chemotherapy (dacarbazine, vincristine, bleomycin and lomustine; BOLD) both combined with interferon-alfa. Serum samples for VEGF-C were analyzed by ELISA. The patients (n =22) with only skin and subcutaneous metastases had significantly lower mean VEGF-C levels (1 643 pg/ml) then the patients (n =42) with other distant metastases (2 584 pg/ml, Mann-Whitney, p =0.033). VEGF-C levels above the median (1 590 pg/ml) were significantly related to deep lymph node involvement (OR 3.763; 95% CI 1.038 − 13.646, p =0.034). There were no other significant associations between VEGF-C levels and tumour burden, nor were the levels significantly related to the response to therapy or survival. Those eight patients, who had received previous adjuvant IFN-alfa therapy had lower mean VEGF-C levels (1 738 pg/ml) as compared to those 56 patients without previous IFN-alfa therapy (2 335 pg/ml, ANOVA, p =0.026). This is the first study exploring serum VEGF-C in melanoma. VEGF-C might be involved in the deep lymphatic dissemination and progression of melanoma metastasis.

Economic evaluation of temozolomide in the treatment of recurrent glioblastoma multiforme

AbstractBackground: Temozolomide (TMZ) is an oral alkylating agent with demonstrated efficacy as therapy for glioblastoma multiforme (GBM) and anaplastic astrocytoma. TMZ has widely replaced the procarbazine, lomustine plus vincristine (PCV) combination for the treatment of malignant brain tumours as a result of its oral administration and favourable toxicity profile. Objectives: This study had three related aims. First, the cost effectiveness of TMZ (from the Finnish healthcare payer perspective) was compared with PCV in patients with GBM that had relapsed after primary treatment with surgery and radiotherapy. Second, the probability that TMZ is cost effective, compared with PCV, was estimated at different societal willingness-to-pay levels. Third, the value of new information for reducing the uncertainty related to the choice of treatment between TMZ and PCV was evaluated. Methods: The cost effectiveness of TMZ and PCV was evaluated using a decision-modelling approach. Incremental cost-effectiveness ratios (ICERs) for cost per gained life-month, progression-free life-month and QALY were calculated. Various information sources were used to acquire parameter values for the model. The efficacy information of both treatments was derived from the medical literature, quality-of-life (QOL) estimates were gathered from Finnish neurooncologists using visual analogue scale methods, and data on the use of healthcare resources were collected from hospital databases. The exact prices for resource use were gained from the list of Finnish health service unit costs (year 2001 prices). The model was analysed using second-order Monte Carlo simulation. The value of new information on reducing uncertainty was analysed using the expected value of perfect information (EVPI) approach. Results: According to the derived ICERs, 1 extra life-month gained with TMZ costs €2367, 1 extra progression-free life-month costs €2165, and 1 extra QALY costs €32 471, compared with PCV, in the treatment of GBM. The probability of TMZ being the most cost-effective choice of treatment was >60% for all levels of willingness to pay >€5000 per gained life-month. The respective probabilities were >75% for all levels of willingness to pay >€10 000 per gained progressionfree life-month and about 85% for all levels of willingness to pay >€20 000 per gained quality-adjusted life-month. According to EVPI analysis, future research would potentially be cost effective if the costs of research were €4.1 million (maximum). Conclusions: On the basis of this Finnish analysis, TMZ has a high probability of being more cost effective than PCV for patients with GBM. The addition of QOL aspects to the prolonging of survival increases the probability further.

High collagenase-1 expression correlates with a favourable chemoimmunotherapy response in human metastatic melanoma.

Matrix metalloproteinases (MMPs) are proteolytic enzymes that can degrade extracellular matrix and thus enhance metastasis. We have studied the expression of two collagenolytic MMPs in 37 samples obtained from 26 patients treated for metastatic melanoma. Interestingly, the samples showed a different expression pattern of collagenase-1 (MMP-1) and collagenase-3 (MMP-13). The samples with high expression levels of MMP-1 (n = 18) were more frequently MMP-13 negative (14 out of 18), whereas those with low expression levels of MMP-1 (n = 15) were predominantly positive for MMP-13 (nine out of 15) (P = 0.027). High expression levels of MMP-1 were associated with a favourable response to chemoimmunotherapy. Responders (n = 13) frequently had intensively MMP-1-expressing metastases (nine out of 13), especially those who achieved a complete response (five out of six). Response failures (n = 7) mainly had metastases with a low intensity of MMP-1 expression (six out of seven) (P = 0.019). There was a tendency towards longer survival among patients with intensively MMP-1-expressing tumours (median 14.3 versus 6.7 months, P = 0.068). The high expression levels of MMP-1 correlated with low MIB-1 (to nuclear antigen Ki-67) (P = 0.019) and positivity for MMP-13 was associated with high MIB-1 expression (P = 0.00048), suggesting that their different expression patterns may affect tumour growth and contribute to differences in patient survival.

Prognostic value of beta1 integrin expression in metastatic melanoma.

&NA; The expression of integrin‐type cell adhesion receptors is frequently changed in malignant transformation. Despite their important role in cancer cell behaviour, the value of integrins as prognostic markers is mostly unknown. We have examined the expression of &bgr;1 integrins in 38 metastatic melanomas obtained from 27 patients treated with combined chemoimmunotherapy. On the basis of &bgr;1 integrin expression, the melanoma samples were divided into two groups: &bgr;1‐negative tumours (< 10% &bgr;1 integrin immunostained cells) and &bgr;1‐positive tumours (with ≥ 10% positive cells). Patients with &bgr;1‐positive tumours (n = 15) had significantly longer disease‐free survival (median 38 versus 7 months, P < 0.0001) and overall survival (median 70 versus 23 months, P = 0.0001) evaluated after the diagnosis of primary disease compared with patients with &bgr;1‐negative metastases (n = 11). Moreover, the survival of the patients with &bgr;1‐positive tumours after the initiation of chemoimmunotherapy was significantly prolonged (median 18 versus 9 months, P = 0.017). The independent nature of &bgr;1 integrin expression as a significant prognostic factor for survival after therapy was confirmed using Coxs multivariate analysis (P = 0.014). Our results indicate that the expression of &bgr;1 integrins might have some major tumour growth regulatory role and can be used as a predictor for prognosis in patients with metastatic melanoma.