Association of expression of metalloproteinases and their inhibitors with the metastatic potential of squamous-cell lung carcinomas. A molecular and immunohistochemical study

Looking at the proteases from a simple perspective

Proteases have received enormous interest from the research and medical communities because of their significant roles in several human diseases. Some examples include the involvement of thrombin in thrombosis, HIV-1 protease in Acquired Immune Deficiency Syndrome, cruzain in Trypanosoma cruzi infection, and membrane-type 1 matrix metalloproteinase in tumor invasion and metastasis. Many efforts has been undertaken to design effective inhibitors featuring potent inhibitory activity, specificity, and metabolic stability to those proteases involved in such pathologies. Protease inhibitors usually target the active site, but some of them act by other inhibitory mechanisms. The understanding of the structure-function relationships of proteases and inhibitors has an impact on new inhibitor drugs designing. In this paper, the structures of four proteases (thrombin, HIV-protease, cruzain, and a matrix metalloproteinase) are briefly reviewed, and used as examples of the importance of proteases for the development of new treatment strategies, leading to a longer and healthier life.

Identification of genes down-regulated during lung cancer progression: a cDNA array study

Background

Lung cancer remains a major health challenge in the world. Survival for patients with stage I disease ranges between 40–70%. This suggests that a significant proportion of patients with stage I NSCLC may actually be under-staged.

Methods

In order to identify genes relevant for lung cancer development, we carried out cDNA array experiments employing 64 consecutive patients (58 men and 6 women) with a median age of 58 years and stage 1 or stage 2 non-small-cell lung cancer (NSCLC).

Results

Basic cDNA array data identified 14 genes as differentially regulated in the two groups. Quantitative RT-PCR analysis confirmed an effective different transcriptional regulation of 8 out of 14 genes analyzed. The products of these genes belong to different functional protein types, such as extra-cellular matrix proteins and proteases (Decorin and MMP11), genes involved in DNA repair (XRCC1), regulator of angiogenesis (VEGF), cell cycle regulators (Cyclin D1) and tumor-suppressor genes (Semaphorin 3B, WNT-5A and retinoblastoma-related Rb2/p130). Some previously described differences in expression patterns were confirmed by our array data. In addition, we identified and validated for the first time the reduced expression level of some genes during lung cancer progression.

Conclusion

Comparative hybridization by means of cDNA arrays assisted in identifying a series of novel progression-associated changes in gene expression, confirming, at the same time, a number of previously described results.

Combinations of three chemotherapeutic agents and two chemotherapeutic agents plus a targeted biologic agent in the treatment of advanced non small-cell lung cancer

Lung cancer is the most common cause of cancer death in the world. In the United States, more than 28% of all cancer deaths are from lung cancer. In the past decade, a number of new drugs were introduced into the treatment of lung cancer including taxanes, gemcitabine, vinorelbine, and irinotecan. Combinations of one of these drugs with cisplatin, with carboplatin, or with one another were shown to be superior to best supportive care, to single-agent cisplatin, and in some instances, to a podophyllotoxin and cisplatin. Comparisons of the various two-drug combinations showed that they are equivalent in efficacy although there are differences in convenience, cost, and toxicity. Many of these two-drug combinations are less toxic than older combinations, which allowed for the development of three-drug combinations that could be given in full dose and with acceptable toxicity. Phase II trials of several three-drug combinations including carboplatin/paclitaxel/gemcitabine and cisplatin/vinorelbine/gemcitabine showed response rates and survival rates that were somewhat higher than anticipated with a two-drug combination. These data led to three randomized trials of a doublet combination versus a triplet combination. Each of these trials showed a higher response rate and higher toxicity rates with the triplet combination. The toxicity rates were still acceptable with the triplet combinations. The survival was also superior in the triplet arms of each of the randomized trials. Unfortunately, the sample size in each of these studies was small and the survival differences are not statistically significant. Therefore, additional larger randomized trials are sorely needed. During the past decade, new molecularly targeted agents were introduced into the treatment of lung cancer and completed phase I and II trials. Objective responses were noted with many of these new agents. Several combinations of doublet chemotherapy with a new targeted agent have completed phase II trials with encouraging results. Some of these new triplets are now in phase III randomized trials.

Bone Sialoprotein Is Predictive of Bone Metastases in Resectable Non–Small-Cell Lung Cancer: A Retrospective Case-Control Study

Purpose

Bone metastases (BM) in non–small-cell lung cancer (NSCLC) may be detected at diagnosis or during the course of the disease, and are associated with a worse prognosis. Currently, there are no predictive or diagnostic markers to identify high-risk patients for metastatic bone dissemination.

Patients and Methods

Thirty patients with resected NSCLC who subsequently developed BM were matched for clinicopathologic parameters to 30 control patients with resected NSCLC without any metastases and 26 patients with resected NSCLC and non-BM lesions. Primary tumors were investigated by immunohistochemistry for 10 markers involved in bone resorption or development of metastases. Differences among groups were estimated by χ2 test, whereas the prognostic impact of clinicopathologic parameters and marker expression was evaluated by univariate (Wilcoxon and Mantel-Cox tests) and multivariate (Cox proportional hazards regression model) analyses.

Results

The presence of bone sialoprotein (BSP) was strongly associated with bone dissemination (P < .001) and, independently, with worse outcome (P = .02, Mantel-Cox test), as defined by overall survival. To evaluate BSP protein expression in nonselected NSCLC, a series of 120 consecutive resected lung carcinomas was added to the study, and BSP prevalence reached 40%. No other markers showed a statistically significant difference among the three groups or demonstrated a prognostic impact, in terms of both overall survival and time interval to metastases.

Conclusion

BSP protein expression in the primary resected NSCLC is strongly associated with BM progression and could be useful in identifying high-risk patients who could benefit from novel modalities of surveillance and preventive treatment.

Tissue MMP-2/TIMP-2-complex are better prognostic factors than serum MMP-2, MMP-9 or TIMP-1 in Stage I–III lung carcinoma

Matrix metalloproteinases (MMPs) are involved in tumor growth and spreading. Here, we investigated the tumor immunoreactive protein of MMP-2, MMP-9 and TIMP-1 as well as the levels of circulating total TIMP-1 and MMP-2/TIMP-2-complex as prognostic factors in lung cancer patients. The material included 59 patients, 30 with a squamous cell carcinoma, 21 with an adenocarcinoma and eight with other histology. Circulating antigens were measured by ELISA assay and the protein expression in primary tumors was analyzed by streptavidin-biotin immunohistochemical staining using specific monoclonal antibodies. The strong positivity for MMP-2 or MMP-9 in tumor predicted poor prognosis. The 5-year survival rates were 83 or 85% in patients negative for MMP-2 or MMP-9, respectively. Only 17% of the patients with a tumor highly positive for MMP-2 and 43% of those with a high positivity for MMP-9 survived at that time (Cox regression P=0.042 for MMP-2 and log rank P=0.046 for MMP-9). On the contrary, strong tissue positivity for TIMP-1 demonstrated a tendency for a favorable survival, although the difference did not reach statistical significance. In patients with a squamous cell carcinoma Stage I, low serum TIMP-1 (<or=300 ng/ml) also predicted unfavorable survival (log rank P=0.033). Further in subgroup of patients treated by lobectomy (n=29), the high levels of circulating MMP-2/TIMP-2-complex (>or=300 ng/ml) associated with an increased survival rate, the 5-year survival being 81 versus 34% (log rank P=0.069) in patients with high or low serum levels for MMP-2/TIMP-2-complex, respectively. Tissue MMP-2 correlated to high expression of MMP-9 immunoreactive protein (P=0.003), but the serum levels of MMP-2/TIMP-2-complex or TIMP-1 did not correlate to the immunostaining of the corresponding tumors. We conclude that in lung carcinoma the best prognostic value is achieved by using immunohistochemistry for MMP-2 and MMP-9. In early disease, however, serum TIMP-1 or MMP-2/TIMP-2-complex could offer some further prognostic value.

Expression of matrix metalloproteinases 7 and 9 in non-small cell lung cancer

Matrix metalloproteinases (MMPs) have been shown to have a significant role in determining cancer cell behaviour. The present study was undertaken to analyze the expression and prognostic value of MMP-7 and MMP-9 in non-small cell lung cancer (NSCLC). The relationship of MMP-7 with beta-catenin was also evaluated. The study consists of 212 patients with resected NSCLC. Tumour samples were stained immunohistochemically, and the expression of MMP-7 and MMP-9 was evaluated in both tumour cells and peritumoural stromal tissue. The results were compared to clinicopathological factors of the patients. A high staining of MMP-7 and MMP-9 in tumour cells was noted in 62 (30%) and 113 (57%) cases, respectively. Expression of MMP-7 was noted more often in adenocarcinomas than in other histological types (p=0.022). High cancer cell associated MMP-7 was related to lower T-factor (p=0.037), better tumour differentiation (p=0.005) and normal beta-catenin expression in tumour cells (p=0.001). A high MMP-9 expression in tumour cells was related to poor tumour differentiation (p=0.016). The stromal signal for MMP-9 was observed in 58 (32%) cases and was linked with higher tumour grade (p=0.031). In survival analyses the significant predictors of survival were histological type of tumour and tumour stage (p=0.0009 and 0.0012, respectively). MMP-7 or MMP-9 signals were not related to patient's outcome. The results show that high MMP-9 expression indicates aggressive, and high MMP-7 less aggressive tumour behaviour in NSCLC. However, MMP-7 and MMP-9 expressions had no prognostic value in NSCLC.

Synthesis of N epsilon-(7-diethylaminocoumarin-3-carboxyl)- and N epsilon-(7-methoxycoumarin-3-carboxyl)-L-Fmoc lysine as tools for protease cleavage detection by fluorescence

Two coumarin-labelled lysines were conveniently prepared as a fluorescence resonance energy transfer (FRET) pair for peptide cleavage detection. 7-Methoxy and 7-diethylamino coumarin-3-carboxylic acids were synthesized according to a modification of known procedures. Labelling at lysine was achieved in solution via the active N-hydroxysuccinimide ester of the carboxylic acid coumarin derivatives to give the target compounds in good yield. Subsequently, these modified amino acids were used in solid phase peptide synthesis (SPPS), and their potential utility in an extracellular matrix metalloprotease (MMP-1) activity measurement via FRET and/or quenching studies was demonstrated.

Phase I trial of the matrix metalloproteinase inhibitor marimastat combined with carboplatin and paclitaxel in patients with advanced non-small cell lung cancer

PURPOSE

Marimastat is an orally bioavailable inhibitor of matrix metalloproteinases. A phase I study was initiated to determine whether conventional doses of carboplatin and paclitaxel are tolerated when combined with marimastat and to assess the influence of marimastat on paclitaxel pharmacokinetics.

EXPERIMENTAL DESIGN

Three dose levels were evaluated. Marimastat (10 or 20 mg oral administration b.i.d.) was administered continuously with paclitaxel (175 or 200 mg/m(2) as a 3-hour i.v. infusion) and carboplatin (at a dose providing an area under the free drug plasma concentration-time curve of 7 mg min/mL) administered each 3 weeks. Toxicity and response were evaluated throughout the intended four cycles of combined therapy. The plasma pharmacokinetics of paclitaxel was determined in each patient both without concurrent marimastat and after receiving marimastat for 1 week.

RESULTS

Twenty-two chemotherapy-naive patients with stage IIIb (27%) or stage IV (73%) non-small cell lung cancer were enrolled. Their median age was 56 years (range, 39-73 years), 50% were female, and their performance status (Eastern Cooperative Oncology Group) ranged from 0 to 2. Treatment was well tolerated, as 18 (82%) of the patients completed all four cycles of chemotherapy without dose-limiting toxicity. Grade 2 musculoskeletal toxicities were reported in 3 of 12 patients receiving marimastat (20 mg b.i.d.). Nine patients required dose reductions, predominantly related to low-grade myelosuppression. Partial responses occurred in 12 of 21 (57%) evaluable patients with disease stabilization in another 5 (19%). Marimastat had no effect on paclitaxel pharmacokinetics.

CONCLUSIONS

The administration of marimastat (10 mg b.i.d.) with paclitaxel (200 mg/m(2)) and carboplatin at an area under the free drug plasma concentration-time curve of 7 mg min/mL was well tolerated with no apparent pharmacokinetic interaction. Study of this drug combination in the adjuvant setting should be considered if tissue inhibition of matrix metalloproteinase activity can first be shown.

Tissue inhibitor of metalloproteinase 1 is an independent predictor of prognosis in patients with nonsmall cell lung carcinoma who undergo resection with curative intent

BACKGROUND

Matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) play a role in the processes of extracellular matrix degradation. Changes in their expression levels have been observed in various tumor types, including lung carcinoma. However, their clinical significance and their prognostic importance in the progression of nonsmall cell lung carcinoma (NSCLC) remain to be specified. In this study, mRNA expression levels of MMP-1, MMP-9, TIMP-1, and TIMP-2 were evaluated in patients with resected NSCLC, and their associations with disease progression and prognosis were determined.

METHODS

Between June 1996 and December 1999, 116 patients underwent resection for NSCLC. Expression levels of MMPs and TIMPs were evaluated using Northern blot analysis in these NSCLC tissue samples and in 39 matched samples of normal lung tissue.

RESULTS

MMP-1, MMP-9, and TIMP-1 expression levels were increased in tumor samples compared with matched, corresponding normal tissues. In contrast, TIMP-2 expression was decreased in tumor samples. MMP-1 tumor expression was correlated significantly with the evolution of lymph node status and tumor-lymph node-metastasis (TNM) stage. In contrast, MMP-9 tumor expression was correlated significantly with increased T stage. TIMP-1 overexpression was an independent predictor of worse survival in patients with NSCLC that was not associated with other prognosis factors, such as TNM stage.

CONCLUSIONS

The overexpression of TIMP-1 was an independent prognostic marker in patients with NSCLC, and evaluating TIMP-1 may be important for identifying patients who are at greater risk of disease recurrence.

MMP-10 is overexpressed, proteolytically active, and a potential target for therapeutic intervention in human lung carcinomas

Matrix metalloproteinase (MMP)-mediated degradation of the extracellular matrix is a major factor for tumor development and expansion. This study analysed MMP-10 protein expression and activity in human lung tumors of various grade, stage, and type to address the relationship between MMP-10 and tumor characteristics and to evaluate MMP-10 as a therapeutic target in non small cell lung carcinoma (NSCLC). Unlike the majority of MMPs, MMP-10 was located in the tumor mass as opposed to tumor stroma. MMP-10 protein was observed at low levels in normal human lung tissues and at significantly higher levels in all types of NSCLC. No correlation was observed between MMP-10 protein expression and tumor type, stage, or lymph node invasion. To discriminate between active and inactive forms of MMP-10 in samples of human NSCLC, we have developed an ex vivo fluorescent assay. Measurable MMP-10 activity was detected in 42 of 50 specimens of lung cancer and only 2 of 10 specimens of histologically normal lung tissue. No relationship was observed between MMP-10 activity levels and clinicopathologic characteristics. Our results suggest that MMP-10 is expressed and active at high levels in human NSCLC compared to normal lung tissues, and, as such, is a potential target for the development of novel therapeutics for lung cancer treatment.

Proteolytic-antiproteolytic balance and its regulation in carcinogenesis

Cancer development is essentially a tissue remodeling process in which normal tissue is substituted with cancer tissue. A crucial role in this process is attributed to proteolytic degradation of the extracellular matrix (ECM). Degradation of ECM is initiated by proteases, secreted by different cell types, participating in tumor cell invasion and increased expression or activity of every known class of proteases (metallo-, serine-, aspartyl-, and cysteine) has been linked to malignancy and invasion of tumor cells. Proteolytic enzymes can act directly by degrading ECM or indirectly by activating other proteases, which then degrade the ECM. They act in a determined order, resulting from the order of their activation. When proteases exert their action on other proteases, the end result is a cascade leading to proteolysis. Presumable order of events in this complicated cascade is that aspartyl protease (cathepsin D) activates cysteine proteases (e.g., cathepsin B) that can activate pro-uPA. Then active uPA can convert plasminogen into plasmin. Cathepsin B as well as plasmin are capable of degrading several components of tumor stroma and may activate zymogens of matrix metalloproteinases, the main family of ECM degrading proteases. The activities of these proteases are regulated by a complex array of activators, inhibitors and cellular receptors. In physiological conditions the balance exists between proteases and their inhibitors. Proteolytic-antiproteolytic balance may be of major significance in the cancer development. One of the reasons for such a situation is enhanced generation of free radicals observed in many pathological states. Free radicals react with main cellular components like proteins and lipids and in this way modify proteolytic-antiproteolytic balance and enable penetration damaging cellular membrane. All these lead to enhancement of proteolysis and destruction of ECM proteins and in consequence to invasion and metastasis.

Novel targeted agents in the treatment of lung cancer

Lung cancer is the leading cause of cancer-related mortality in the US. Although an improvement in outcome is possible with the continued advancement of cytotoxic-based treatment, clinical research is currently focused on utilising novel molecular targets with proven efficacy in preclinical models and a low toxicity profile. This is the result of advances in understanding of tumour biology and molecular pathways that have been implicated in cancer pathogenesis and progression. Novel agents targeting cell cycle regulation, angiogenesis and signal transduction pathways have reached clinical testing in lung cancer and are discussed in this review.

Chemically modified tetracyclines as inhibitors of matrix metalloproteinases

Matrix metalloproteinases belong to a diverse group of enzymes that are not only involved in restructuring the extracellular matrix, but also play a major role in various pathophysiological conditions by virtue of their complicated expression, activation, and regulation processes. They have been widely implicated to function as major contenders in cancer progression, frequently due to their role in invasion, proliferation and metastasis. MMP inhibitors have been specifically designed to target these altered activities of MMPs, mostly by means of inhibiting their function and by diminishing their increased expression in various disease states, particularly cancer. Tetracyclines and chemically modified tetracyclines (CMTs) have been rationally designed to inhibit the activity of MMPs and thus decrease the potential risk of spread of tumor cells to distant sites by invasion and metastasis. Pre-clinical and early clinical data for one of these CMTs, COL-3 (formerly CMT-3) indicate considerable potential for this group of anticancer agents. Further testing and rational modifications of these CMT analogues might lead to new anticancer agents.

Targeting angiogenesis: a review of angiogenesis inhibitors in the treatment of lung cancer

It has now been almost 30 years since Dr J. Folkman first proposed that inhibition of angiogenesis could play a key role in treating cancer; however, it is only recently that anti-angiogenesis agents have entered the clinical setting. The search for novel therapies is particularly important in lung cancer, where the majority of patients succumb to their disease despite aggressive treatments. Several classes of agents now exist that target the different steps involved in angiogenesis. These include drugs inhibiting matrix breakdown, the matrix metalloproteinase inhibitors (MMPIs), such as marimastat, prinomastat, BMS275291, BAY12-9566, and neovastat drugs that block endothelial cell signaling via vascular endothelial growth factor (VEGF) and its receptor (VEGFR) including rhuMAb VEGF, SU5416, SU6668, ZD6474, CP-547,632 and ZD4190. Drugs that are similar to endogenous inhibitors of angiogenesis including endostatin, angiostatin and interferons. There has also been renewed interest in thalidomide. Drugs such as squalamine, celecoxib, ZD6126, TNP-470 and those targeting the integrins are also being evaluated in lung cancer. Despite early enthusiasm for many of these agents, Phase III trials have not yet demonstrated significant increases in overall survival and toxicity remains an issue. It is hoped that as our understanding of the complex process of angiogenesis increases, so will our ability to design more effective targeted therapies.

Angiogenesis inhibitors under study for the treatment of lung cancer

Several classes of agents now exist that target the different steps involved in angiogenesis. These include drugs inhibiting matrix breakdown, the matrix metalloproteinase inhibitors (MMPIs), such as marimastat, prinomastat, BMS275291, BAY12-9566, and neovastat. Trials of this class of agents have all been negative to date. Drugs that block endothelial cell signaling via vascular endothelial growth factor (VEGF) and its receptor (VEGFR) including rhuMAb VEGF, SU5416, SU6668, ZD6474, CP-547,632 and ZD4190 are all in earlier stages of clinical trial. Drugs that are similar to endogenous inhibitors of angiogenesis including interferons have also been evaluated without success. Endostatin has been shown to have an acceptable toxicity profile, but clinical evidence of activity has not yet been demonstrated. There has also been renewed interest in thalidomide. Drugs such as squalamine, celecoxib, ZD6126, TNP-470 and those targeting the integrins are also being evaluated in lung cancer. Despite early enthusiasm for many of these agents, Phase III trials have not yet demonstrated significant increases in overall survival and toxicity remains an issue. It is hoped that as our understanding of the complex process of angiogenesis increases, so will our ability to design more effective targeted therapies.

Prospective, randomized, double-blind, placebo-controlled trial of marimastat after response to first-line chemotherapy in patients with small-cell lung cancer: a trial of the National Cancer Institute of Canada-Clinical Trials Group and the European Organization for Research and Treatment of Cancer

PURPOSE

Increased expression of metalloproteinases is associated with poor prognosis in small-cell lung cancer (SCLC). This trial was undertaken to determine whether adjuvant treatment with the metalloproteinase inhibitor marimastat could prolong survival in responding patients with SCLC after chemotherapy.

PATIENTS AND METHODS

SCLC patients in complete or partial remission were eligible. They were stratified by radiotherapy (early, late, or none), stage (extensive or limited), response (complete or partial), and cooperative group (National Cancer Institute of Canada-Clinical Trials Group or European Organization for Research and Treatment of Cancer). They were randomized to receive marimastat 10 mg or placebo orally bid for up to 2 years.

RESULTS

There were 532 eligible patients (266 marimastat and 266 placebo). Stage was limited for 279 patients (52%) and extensive for 253 (48%). Best response to induction therapy was complete remission for 176 patients (33%), partial remission for 341 (64%), and 15 patients (3%) had undergone surgical resection. The median time to progression for marimastat patients was 4.3 months compared with 4.4 months for placebo patients (P =.81). Median survivals for marimastat and placebo patients were 9.3 months and 9.7 months, respectively (P =.90) Toxicity was generally limited to musculoskeletal symptoms (18% grade 3/4 for marimastat). Dose modifications for musculoskeletal toxicity were required in 90 patients (33%) on the marimastat arm, and 87 (32%) permanently stopped marimastat because of toxicity. Patients on marimastat had significantly poorer quality of life at 3 and 6 months.

CONCLUSION

Treatment with marimastat after induction therapy for SCLC did not result in improved survival and had a negative impact on quality of life.

Development of matrix metalloproteinase inhibitors in cancer therapy

The matrix metalloproteinases represent an attractive target for cancer treatment, and a number of matrix metalloproteinase inhibitors are undergoing clinical trials. The results of these studies will establish whether any of these compounds are therapeutically useful. Independent of the conclusions from the first generation of studies, the field of matrix metalloproteinase inhibitors remains attractive for creative and innovative research. In the future, the development of novel, less toxic, and more effective matrix metalloproteinase inhibitors, and the combination of conventional agents with these novel anticancer agents will constitute the main focus of research efforts.

Identification of differentially expressed genes in pulmonary adenocarcinoma by using cDNA array

No clear patterns in molecular changes underlying the malignant processes in lung cancer of different histological types have been found so far. To identify critical genes in lung cancer progression we compared the expression profile of cancer related genes in 14 pulmonary adenocarcinoma patients with normal lung tissue by using the cDNA array technique. Principal component analyses (PCA) and permutation test were used to detect the differentially expressed genes. The expression profiles of 10 genes were confirmed by semi-quantitative real-time RT-PCR. In tumour samples, as compared to normal lung tissue, the up-regulated genes included such known tumour markers as CCNB1, PLK, tenascin, KRT8, KRT19 and TOP2A. The down-regulated genes included caveolin 1 and 2, and TIMP3. We also describe, for the first time, down-regulation of the interesting SOCS2 and 3, DOC2 and gravin. We show that silencing of SOCS2 is not caused by methylation of exon 1 of the gene. In conclusion, by using the cDNA array technique we were able to reveal marked differences in the gene expression level between normal lung and tumour tissue and find possible new tumour markers for pulmonary adenocarcinoma.

Determination of cathepsin B expression may offer additional prognostic information for ovarian cancer patients

The lysosomal cysteine proteinase cathepsin B has been implicated in the progression of various human tumors including ovarian cancer. Included in this study were 63 patients with epithelial ovarian carcinoma. Follow-up information (median follow-up period 7 years) was available for all patients, among whom 42 (66.7%) had relapsed and 32 (50.8%) had died. The immunohistochemistry method was adopted for the detection of cathepsin B using paraffin embedded specimens. Results were compared to clinico-pathological data. Statistical analysis showed cathepsin B expression to be significantly associated with the stage of disease, debulking success and interestingly, with progesterone receptors. It was also inversely related to progression-free survival (PFS) and overall survival (OS). Accordingly, cathepsin B can be regarded as unfavorable and as an independent tumor marker for progression-free survival and overall survival in ovarian cancer patients with long follow-up.

The Role of Farnesyltransferase Inhibitors in Lung Cancer Therapy

Protein farnesylation is required for the localization and function of several proteins pivotal to signal transduction pathways and cytoskeletal organization, including the Ras proteins. Ras proteins are constitutively activated in 30% of human tumors, including lung cancer tumors, as a consequence of mutations in ras genes. Farnesyltransferase inhibitors (FTIs) were thus designed to curtail the Ras-mediated aberrant signals that regulate cell proliferation, apoptosis, invasion, and angiogenesis. These processes are vital to the perpetuation of the malignant phenotype. However, current evidence suggests that the antitumor activity of FTIs is Ras-independent. This article reviews preclinical and clinical data pertinent to the use of FTIs in lung cancer.

Expression of membrane-type-1-matrix metalloproteinase and metalloproteinase-2 in nonsmall cell lung carcinomas

For the metastasis and invasion of cancer cells, destruction of extracellular matrix is essential. In this process, collagen is broken down by some matrix metalloproteinases. Matrix metalloproteinase 2 (MMP2) is able to cleave type IV collagen, and membrane-type-1-matrix metalloproteinase (MT1-MMP) induces activation of proMMP2. We investigated the expressions of MT1-MMP and MMP2 and their relation to both clinicopathologic parameters and clinical outcome in non-small cell lung carcinomas (NSCLC). Eighty-nine specimens of NSCLC were examined using in situ hybridization and immunohistochemistry. Each metalloproteinase was expressed within the cytoplasm of tumor cells with or without stromal cells in NSCLC. Tumors in which tumor cells strongly stained for MT1-MMP mRNA or protein made up more than 50% of the tumor area were found in 44 and 26% of cases, respectively. The corresponding values for MMP-2 mRNA and protein, were 51 and 26%. Our analysis of clinicopathological findings revealed a significant positive relationship between MT1-MMP mRNA and p-M. The correlation between MMP2 protein-staining status and overall survival rate reached significance in the univariate analysis. However, an association was not demonstrated in the multivariate analysis. The detection of MT1-MMP and MMP2 is likely to be of limited value in informing the prognosis in NSCLC.

Novel approaches to the treatment of non-small cell lung cancer

Prognosis of non-small cell lung carcinomas (NSCLC) remains poor, especially in advanced disease. The introduction of new cytotoxic agents in the past decade did only attain minor improvements in survival. It is rather clear that chemotherapy may have reached a plateau, and that it will be difficult to obtain better results in advanced NSCLC by chemotherapy alone. Novel treatment modalities are urgently needed in advanced NSCLC. Backed-up by advances in the understanding of tumor cell biology, a new generation of anticancer agents specifically directed at targets such as tyrosine kinases, farnesyl transferase, angiogenesis factors, matrixmetalloproteinases and oncogenes has been developed in recent years. In this review, we give a brief summary of the state-of-the-art treatment of NSCLC, highlighting its limitations. Novel systemic approaches are then discussed in detail with focus on their mechanistic rationale, stage of clinical development and possible drawbacks. Finally, perspectives of future applications and impact on the treatment of NSCLC are also discussed.

Angiogenesis inhibitors in the treatment of lung cancer

Numerous inhibitors of angiogenesis are currently under study in lung cancer. Four trials of adjuvant interferon after chemotherapy for small cell lung cancer (SCLC) were negative. Several metalloproteinase inhibitors (MMPIs) are now in study in SCLC and non-small cell lung cancer (NSCLC). Two large randomized trials have closed recently in which Marimastat 10 mg bid was compared to placebo in responding patients with SCLC. Two randomized studies of Prinomastat versus placebo with combination chemotherapy in advanced NSCLC have also completed accrual. The results of these trials are not yet available, but should be reported in mid-2001. A Phase III trial of BMS-275291, a broad-spectrum MMPI in combination with paclitaxel and carboplatin is open for patients with advanced NSCLC. Neovastat, a standardized shark cartilage extract is under study in inoperable Stage III NSCLC. VEG-F gene expression is increased in many tumors including NSCLC, and may act as a paracrine mediator of growth. A randomized Phase II trial of paclitaxel and carboplatin with or without a recombinant humanized anti-VEG-F has been undertaken in NSCLC. Modestly better response and survival were seen with anti-VEG-F and a large Phase III trial is planned. Numerous receptor tyrosine kinases (TK) have been found to be directly or indirectly involved in angiogenesis including Flk-1, Flt-l, Tie-1 and Tie-2. SU5416 is a small molecular TK inhibitor and potent inhibitor of VEG-F-mediated Flk-1 receptor signaling. Another TK inhibitor SU6668 blocks VEG-F, bFGF and PDGF receptor signaling. It is orally available, and it may be evaluated in lung cancer trials in the near future. ZD4190 is an inhibitor of KDR/Flk-1 that may be evaluated in SCLC. Thalidomide has recently been shown in pre-clinical models to be anti-angiogenic. A randomized trial of paclitaxel/carboplatin and radiation with or without thalidomide is open for patients with Stage IIIB NSCLC in the United States. Numerous other anti-angiogenesis agents are in early clinical trials, but have not been evaluated in lung cancer yet.

Angiogenesis as a biomarker and target in cancer chemoprevention

Angiogenesis, the formation of new blood vessels from existing vasculature, is essential to the late stages of carcinogenesis, allowing tumours to grow beyond 1-2 mm in diameter, invade surrounding tissue, and metastasise. However, more than two decades ago, angiogenesis that preceded neoplastic transformation was seen. Indeed, it can be detected in inflammatory and infectious diseases that increase the risk of developing cancer. Recent advances in fluorescence endoscopy and histological assessment suggest that, for certain cancers, the degree of new blood-vessel formation may differ between the early and late stages of carcinogenic progression. The association between angiogenesis and cancer occurrence, and ease of detection of this process in accessible tissues early in carcinogenesis, mean that angiogenesis fulfils the criteria for a biomarker of the effectiveness of chemopreventive intervention. There is also some evidence that biochemical assays of angiogenic growth factors may offer similar potential as surrogate biomarkers. Many natural and synthetic chemopreventive agents in development or in clinical use inhibit new vessel formation in vivo. Validation of angiogenesis as a biomarker for the effectiveness of chemoprevention should further the advancement of some chemopreventive agents.

Overexpression of matrix-metalloproteinase-9 in human breast cancer: a potential favourable indicator in node-negative patients

Matrix metalloprotease-9 (MMP-9; 92 kDa type IV collaganase, gelatinase B) is regarded as, important for degradation of the basement membrane and extracellular matrix during cancer invasion and other tissue-remodelling events. In this study we evaluate the prognostic value of MMP-9, by immunoperoxidase staining in a series of 210 breast cancer tissues. The results were quantitated using the HSCORE system, which consider both staining intensity and the percentage of cells stained at given intensities. MMP-9 status was compared with the concentration of cytosolic Cathepsin-D and with other established prognostic factors, in terms of disease free survival and overall survival. The median follow-up period was 62 months. MMP-9 staining was observed primarily in cancer cells, and to a lesser degree in surrounding stromal cells. MMP-9 expression was not detected in normal breast tissue. Levels of MMP-9 expression below the cut-off point were more frequently observed in larger (P = 0.014), invasive ductal histologic (P = 0.037), progesterone receptor (PR)-negative and PR-strong positive tumours (P< 0.001), as well as samples belonging to patients with stage III-IV disease (P = 0.009) and age 45-55 years (P = 0.011). In univariate analysis, node-negative breast cancer patients with tumors positive for MMP-9 had a considerable reduction in risk for relapse (RR = 0.45;P = 0.039) or death (RR = 0.32;P = 0.009). Multivariate analysis indicated that MMP-9 status was an independent favourable predictor of OS (RR = 0.47;P = 0.034) in node-negative but not in node-positive patients. Our results suggest that MMP-9 may be an independent favourable prognostic factor in node-negative breast cancer patients. The overexpression of MMP-9 in breast cancer may be also used as a marker to subdivide node negative breast cancer patients in order to determine the optimal treatment modality.

Development of matrix metalloproteinase inhibitors in cancer therapy

The matrix metalloproteinases (MMPs) are a family of zinc-dependent proteinases involved in the degradation of the extracellular matrix. The MMPs have been implicated in the processes of tumor growth, invasion, and metastasis; are frequently overexpressed in malignant tumors; and have been associated with an aggressive malignant phenotype and adverse prognosis in patients with cancer. A number of MMP inhibitors are being developed for the treatment of cancer. The most extensively studied class of MMP inhibitors includes collagen peptidomimetics and nonpeptidomimetic inhibitors of the MMP active site, tetracycline derivatives, and bisphosphonates. The hydroxamate peptidomimetic inhibitor batimastat and its orally bioavailable analogue marimastat, which bind covalently to the zinc atom at the MMP-active site, were the first MMP inhibitors to be studied in detail. Marimastat is currently being studied in randomized clinical trials. The nonpeptidic MMP inhibitors were synthesized in an attempt to improve the oral bioavailability and pharmaceutical properties of the peptidic inhibitors. Several members of this class of compounds are undergoing evaluation in phase III clinical trials. The tetracyclines and, particularly, the nonantibiotic chemically modified tetracyclines, interfere with several aspects of MMP expression and activation and inhibit tumor growth and metastases in preclinical models. A representative agent of this class, Col-3, is currently undergoing phase I clinical trials. The development of the MMP inhibitors, like that of other targeted and predominantly antiproliferative compounds, poses a challenge because the paradigms that have governed the design of clinical oncology trials may not be relevant to this new class of agents. The anticipated need for long-term administration of these drugs, together with their cytostatic mechanism of action, will require novel clinical trial design strategies.

Expression of matrix metalloproteinase-2 (MMP-2) and of membrane-type-1-matrix metalloproteinase (MT1-MMP) in transitional cell carcinoma of the upper urinary tract

Tumor cell invasion and metastasis are biologically dependent on the proteolytic destruction of surrounding matrix components. Matrix metalloproteinase-2 (MMP-2) is able to cleave type IV collagen, and membrane-type-1-matrix metalloproteinase (MT1-MMP) induces activation of proMMP-2. We investigated the expression of MMP-2 and MT1-MMP using in situ hybridization and immunohistochemistry in 102 cases of transitional cell carcinoma of the upper urinary tract (TCC-UUT). A positive expression of each metalloproteinase was recognized in all samples and was apparent within the cytoplasm of tumor epithelial cells and/or stromal cells situated at the interface between tumor and stroma. Our analysis of clinicopathologic findings showed a relationship between MMP-2 and MT1-MMP expression and stage. The correlation between the MMP-2 protein staining score for tumor epithelial cells and overall survival rate reached significance in the univariate analysis. However, only stage was associated with disease-free and overall survivals in the multivariate analysis. In conclusion, the detection of MMP-2 and MT1-MMP would appear to be of limited value in informing the prognosis of TCC-UUT.

Matrix metalloproteinases and their inhibitors in tumour growth and invasion

Controlled degradation of the extracellular matrix (ECM) is crucial for the growth, invasive capacity, metastasis and angiogenesis of tumours. Matrix metalloproteinases (MMPs), a family of zinc-dependent neutral endopeptidases that are collectively capable of degrading essentially all ECM components, apparently play an important role in all of these aspects of tumour development. In addition, there is recent evidence that MMPs are also important for tumour cell survival. At present, therapeutic intervention on tumour growth and invasion based on the inhibition of MMP activity is under intensive investigation, and several MMP inhibitors are already being used on malignant tumours of various organs in clinical trials. In this review we discuss the role of MMPs and their inhibitors in tumour invasion as a basis for prognostic purposes and for targeted therapeutic intervention in cancer.