Vinblastine, Vincristine and Vindesine: anti-invasive effect on MO4 mouse fibrosarcoma cells in vitro

Vincristine enhances amoeboid-like motility via GEF-H1/RhoA/ROCK/Myosin light chain signaling in MKN45 cells

Background

Anti-cancer drugs are widely used in cancer treatment frequently combined with surgical therapy and/or radiation therapy. Although surgery and radiation have been suggested to facilitate invasion and metastasis of tumor cells in some cases, there is so far little information about the effect of anti-cancer drugs on cellular invasive ability and metastasis. In this study, using four different anti-cancer drugs (vincristine, paclitaxel, cisplatin and etoposide), we examined whether these drugs influence the invasive ability of tumor cells.

Methods

Human gastric adenocarcinoma MKN45 cells were used to evaluate the effect of anti-cancer drugs. After drug treatment, cellular invasive ability was assessed using the Matrigel invasion chamber. Cytoskeletal changes after treatment were examined microscopically with F-actin staining. In addition, we monitored cellular motility in 3D matrigel environment by time-lapse microscopic analysis. The drug-induced activation of RhoA and ROCK was evaluated by pull-down assay and Western blotting using an antibody against phosphorylated myosin light chain (MLC), respectively. Where necessary, a ROCK inhibitor Y27632 and siRNA for guanine nucleotide exchange factor-H1 (GEF-H1) were applied.

Results

Among all drugs tested, only vincristine stimulated the invasive ability of MKN45 cells. Microscopic analysis revealed that vincristine induced the formation of non-apoptotic membrane blebs and amoeboid-like motility. Vincristine significantly enhanced RhoA activity and MLC phosphorylation, suggesting the involvement of RhoA/ROCK pathway in the vincristine-induced cytoskeletal reorganization and cellular invasion. Furthermore, we found that Y27632 as well as the siRNA for GEF-H1, a RhoA-specific activator, attenuated MLC phosphorylation, the formation of membrane blebs and the invasive ability after vincristine treatment.

Conclusions

These results indicate that vincristine activates GEF-H1/RhoA/ROCK/MLC signaling, thereby promoting amoeboid-like motility and the invasive ability of MKN45 cells.

The radiation response of sarcomas by histologic subtypes: a review with special emphasis given to results achieved with razoxane

Purpose. Relatively few results are available in the literature about the radiation response of unresectable sarcomas in relation to their histology. Therefore, an attempt was made to summarize the present situation. Materials and methods. This report is based on a review of the literature and the author's own experience. Adult-type soft tissue sarcomas, chondrosarcomas, and chordomas were analyzed. Radioresponse was mainly associated with the degree of tumor shrinkage, that is, objective responses. Histopathologic responses, that is, the degree of necrosis, are only discussed in relation to radiation treatment reports of soft tissue sarcomas as a group. Results. Radiation therapy alone leads to major responses in about 50% of lipo-, fibro-, leiomyo-, or chondrosarcomas. The response rate is less than 50% in malignant fibrous histiocytomas, synovial, neurogenic, and other rare soft tissue sarcomas. The response rates may increase up to 75% through the addition of radiosensitizers such as halogenated pyrimidines or razoxane, or by the use of high-LET irradiation. Angiosarcomas become clearly more responsive if biologicals, angiomodulating, and/or tubulin affinic substances are given together with radiation therapy. Razoxane is able to increase the duration and quality of responses even in difficult-to-treat tumors like chondrosarcomas or chordomas. Conclusions. The available data demonstrate that the radioresponsiveness of sarcomas is very variable and dependent on histology, kind of radiation, and various concomitantly given drugs. The rate of complete sustained remissions by radiation therapy alone or in combination with drugs is still far from satisfactory although progress has been made through the use of sensitizing agents.

Treatment of vascular soft tissue sarcomas with razoxane, vindesine, and radiation

PURPOSE

In previous studies, razoxane and vindesine together with radiotherapy was proved to be effective in soft tissue sarcomas (STS). Because razoxane leads to a redifferentiation of pathological tumor blood vessels, it was of particular interest to study the influence of this drug combination in vascular soft tissue sarcomas.

METHODS AND MATERIALS

This open multicenter Phase II study was performed by the Austrian Society of Radiooncology. Among 13 evaluable patients (10 angiosarcomas and 3 hemangio-pericytomas), 9 had unresectable measurable disease, 3 showed microscopic residuals, and 1 had a resection with clear margins. They received a basic treatment with razoxane and vindesine supported by radiation therapy. Outcome measures were objective response rates, survival time, and the incidence of distant metastases.

RESULTS

In nine patients with measurable vascular soft tissue sarcomas (eight angiosarcomas and one hemangiopericytoma), 6 complete remissions, 2 partial remissions, and 1 minor remission were achieved, corresponding to a major response rate of 89%. A maintenance therapy with razoxane and vindesine of 1 year or longer led to a suppression of distant metastases. The median survival time from the start of the treatment is 23+ months (range, 3-120+) for 12 patients with macroscopic and microscopic residual disease. The progression-free survival at 6 months was 75%. The combined treatment was associated with a low general toxicity, but attention must be given to increased normal tissue reactions.

CONCLUSIONS

This trimodal treatment leads to excellent response rates, and it suppresses distant metastases when given as maintenance therapy.

Combined vindesine and razoxane shows antimetastatic activity in advanced soft tissue sarcomas

BACKGROUND

Razoxane and vindesine were shown to suppress distant metastasis in animal systems. Both drugs affect main steps of the metastatic cascade. Therefore, a pilot study was performed to study the influence of these drugs on the dynamics of metastasis in advanced soft tissue sarcomas (STS). This study was now updated.

METHODS

Twenty-three patients with unresectable (n = 7) and oligometastatic STS (n = 16) received a basic treatment with razoxane and vindesine supported by radiotherapy and occasionally by surgery. Long-term treatment was intended in patients with metastatic disease. The cumulative number of new metastases after 6 and 9 months were determined. Thirty-six patients with comparable stages of STS treated with contemporary chemotherapy served as non-randomized, retrospective controls. The prognostic parameters of the groups were comparable.

RESULTS

In patients receiving razoxane and vindesine, the median number of new metastases after 6 months was 0 (range, 0-40) and after 9 months likewise 0 (0-70). The corresponding numbers in the control group were 4.5 (range, 0-40) and 9 (0->100) (P < 0.001). The progression-free survival at 6 months was 74% in the study group and 23% in the controls. The median survival time from the occurrence of the first metastasis or the time of unresectability was 20+ months (range, 8-120+) versus 9 months (range, 2-252) (P < 0.001). The combined treatment was associated with a low to moderate toxicity.

CONCLUSIONS

Trimodal treatment with razoxane, vindesine, and radiotherapy is feasible in patients with unresectable primaries and early metastatic STS. The combination inhibits the development of remote metastases in a majority of the patients and prolongs survival.

Cytoplasmic microtubules in two different mouse melanoma cell lines: a qualitative and quantitative analysis using confocal laser scanning microscopy and computer-assisted image analysis

The microtubular system as one part of the cellular cytoskeleton is not only necessary for mitotic activity of malignant cells but also for invading neighboring tissues and for the formation of distant metastases. In the present study, the amount and distribution of tubulin in two murine melanoma cell lines (K1735-M2: high metastatic clone; K1735-c116: low metastatic clone) were determined quantitatively using an indirect immunofluorescence technique, confocal laser scanning microscopy (CLSM) and computer-assisted image analysis. Additionally, qualitative and quantitative changes after application of the microtubule-inhibitor nocodazole were investigated. Quantitative analysis showed a significant difference between the high and low metastatic cell line for the parameter TEXTURE, indicating a finer structured network within the high metastatic cells. After treatment with nocodazole the parameters TEXTURE and DENSITY were reduced, suggesting a decrease of assembled tubulin and a less delicate structure of the remaining microtubules. Our study shows that CLSM combined with computer-assisted image analysis provides a new method to examine quantitative variations of the cytoskeleton possibly related to cell function.

The influence of the protease inhibitor aprotinin on tumor invasion of three cell lines in vitro

The production of protease by malignant cells has been held responsible for invasion. The effect of aprotinin, a broad-spectrum protease inhibitor, on malignant invasion was examined histologically in organotypical cocultures of precultured embryonic chick heart fragments with two human melanoma cell lines and one virus-transformed fetal mouse carcass cell line. In the presence of 400 KIU/ml aprotinin, invasion was still permissive, while in the comparison with 0.1 microgram/ml vincristine, a microtubule and directional motility inhibitor and a well-documented anti-invasive agent, invasion was completely stopped. Aprotinin remained stable in the culture medium so that the presence of invasion cannot be explained by low drug concentration. It is concluded that aprotinin-sensitive proteases are not implicated in invasion in vitro in the cell types investigated, and that this in vitro technique deserves further interest for the study of protease inhibitors in the mechanism of invasion.

Is adjuvant treatment with vinblastine effective in reducing the occurrence of distant metastasis in limited squamous cell lung cancer? A randomized study

In order to study the usefulness of treatment with vinblastine (VLB) in the prevention of cancer metastasis in squamous cell lung cancer, 50 patients with locoregional disease were randomized to receive either locoregional RT alone (group A) or a weekly intravenous bolus injection of VLB (6 mg/m2) concurrently with and after locoregional radiotherapy (RT) (55 Gy in 6 weeks) until the appearance of metastases (group B). Neither the incidence of death with metastases, metastasis-free survival (MFS) nor overall survival (S) were significantly affected by treatment with the drug. However, due to the limited number of patients in each group, the power of the statistical test was such to allow only the detection of differences in MFS and S to or more than 80 per cent at the P = 0.05 level. Local tumor response was significantly superior in group B (P less than 0.05). Acute toxicity (dysphagia, myelosuppression) during RT was significantly worse in group B. During long-term therapy with VLB, mild polyneuropathy developed in the majority of patients in group B. Furthermore, seven patients discontinued treatment with VLB during maintenance due to compliance (4) and excessive neurotoxicity (3). This treatment schedule with VLB is not recommended for patients with locoregional squamous cell lung cancer as significant toxicity is present during and after RT and significant increase in MFS and S is lacking. Because of an apparent increase in local response, the combination of VLB and RT merits further investigation in those tumors where local tumor control is crucial.

Quantitative analysis of cancer invasion in vitro: comparison of two new assays and of tumour sublines with different metastatic capacity

Various murine tumour sublines which differed considerably in their in vivo metastatic capacity were tested in vitro for their ability to invade normal tissue. For this purpose we developed two quantitative tests, a Boyden chamber endothelial cell invasion assay and a brain tissue microsphere invasion assay. The invasion of [75Se]methionine-prelabelled tumour cells into the normal tissues was followed by measuring the percentage of tumour-associated label in the brain microspheres or the endothelial monolayers after 12-48 h of co-cultivation. Clear and comparable differences existed in both assays between the amount of radiolabel found in the normal tissues after a co-cultivation with the different tumour lines. In three of the four tumour lines invasiveness correlated with metastatic capacity. The fourth line, a plastic adherent variant, was highly invasive but low metastatic. The ability of tumour cells to invade normal tissue, therefore, while necessary for the generation of metastases, is not in itself sufficient. Since both assays are independent of time-consuming histological sectioning and staining and allow a quantitative determination of invasive capacity of tumour cells grown as single cell suspensions they appear well suited for experimental manipulation and for screening of anti-invasive drugs.

Shaping future strategies for the pharmacological control of tumor cell metastases

The eradication of established metastases in patients with malignant tumors is the single most important objective in clinical oncology. The current panel of antineoplastic agents discovered through random and semiempirical screening procedures has proven largely ineffective in treating disseminated disease and there is a clear and urgent need for more efficient antimetastatic drugs. Unfortunately, although progress has been made in examining the biology of metastatic spread, our understanding of the pharmacology, biochemistry and molecular genetics of this process is meager and insufficient to provide a rational foundation for the design of mechanism-based antineoplastic agents. Faced on the one hand with the failure of existing drugs to control metastatic spread and on the other with a dearth of alternative pharmacological approaches, the prospect of offering significantly improved therapy to the cancer patient of the 1990's is poor. The challenge of the coming decade lies in obtaining better insights into the molecular mechanisms of metastasis and using this information to identify pharmacological opportunities to curtail the proliferation of secondary tumor growths. As a first step toward this goal we need to define more rigorously what constitutes a therapeutic target in malignant disease and what steps in the pathogenesis of cancer metastasis represent the gravest risk to the patient and thus are most eligible for direct pharmacological intervention. In addressing these issues and developing future strategies for antimetastatic drugs, Paget's 100 year-old 'seed and soil' hypothesis continues to offer a useful conceptual framework for analysis of metastatic behavior. Although Paget's proposal has been validated by a century of clinical observation, efforts to define the 'seed and soil' theory in molecular terms have not been attempted. With the advent of more efficient methodologies for culturing human normal and neoplastic cells coupled with the availability of microanalytical technologies it now becomes possible to investigate and identify the complementary biochemical components of the tumor cell 'seed' and organ 'soil' that combine to encourage the proliferation of metastases. With this information the design of specific pharmacological strategies to uncouple the 'seed and soil' relationship may emerge as a potential therapeutic approach for antagonizing the growth of disseminated malignant tumors.

High-performance liquid chromatographic determination of vinca-alkaloids in plasma and urine

A liquid chromatographic method is described for separating and determining vinblastine, vincristine and vindesine in plasma and urine. The drugs are extracted from the biological material using an ion-pair extraction, with sodium octylsulphate as counter-ion at pH 3. The extracts are injected on a reversed-phase system with a cyano column as stationary phase and a mobile phase composed of acetonitrile-phosphate buffer, pH 3 (65:35, vol. %). Stability studies are carried out for stock solutions of the drugs in water at different temperatures and pH values. The stability of these compounds in plasma is also investigated in the presence of an antioxidant. The method is applied to determine drug levels of vindesine and vinblastine in preliminary pharmacokinetic studies, using vincristine as the internal standard.

An image analysis system for the quantification of invasion in vitro

We have tested the value of a computer-assisted image analysis program for the quantitative study of invasion in vitro using experiments that were previously described semi-quantitatively. Mouse fibrosarcoma cell (MO4) aggregates were confronted with precultured fragments of embryonic chick heart in organ culture. Confronting pairs were fixed after 1, 2, 3 and 4 days, and processed for paraffin sectioning and immunostaining with an antiserum against chick heart. The image analysis system allowed separate quantification of two aspects of invasion, namely, occupation of the heart tissue by MO4 cells and degeneration of the invaded heart tissue. Complex combination of occupation and invasion added a qualitative aspect of invasion that has not been described previously and that revealed qualitative differences in invasion under various circumstances.

Temperature-dependent metastasis of the Lucke renal carcinoma and its significance for studies on mechanisms of metastasis

Metastasis is temperature dependent in the renal adenocarcinoma of the North American leopard frog, Rana pipiens. Widespread, multiple, metastatic colonies occur in tumor-bearing frogs kept at 28 degrees C for 50 days while tumor-bearing frogs kept at 7 degrees C for 98 days or more have either no secondary deposits or they have only an occasional small metastatic nodule. An attractive aspect of the frog tumor is that invasion and metastasis can be permitted or inhibited by the manipulation of temperature alone-no exogenous chemicals or drugs are required for the effect. Because of this, biological variables which reproducibly and specifically associate with metastasis permissive conditions when ambient temperature is cycled between permissive and inhibitory values are strong candidates for being causal elements in the multistep process leading to metastasis. Intravascularly injected labelled renal tumor cells reached all organs studied in as little as 15 minutes at both metastasis restrictive and permissive temperature. The results with tumor cell inoculation dispose of the possibility that failure of metastasis in chilled animals is due to cold-induced changes in blood flow. Histologically typical metastatic colonies developed in frogs, kept at the permissive temperature, after injection with disaggregated tumor cells which were previously cryopreserved. Frog tumors elaborate type I collagenase in a temperature dependent manner. Type IV collagenase has been demonstrated as well. Tumor cell detachment in vitro, assembly and disassembly of tumor cell cytoplasmic microtubules, and invasion in vitro, are all temperature dependent.

Invasiveness and tumorigenicity of MO4 mouse fibrosarcoma cells pretreated with microtubule inhibitors

MO4 cell aggregates with a diameter of 0.3 mm produced invasive fibrosarcomas after s.c. implantation into the pinna of syngeneic mice. Histology of pinnae fixed 10 min to 5 days after implantation of an aggregate suggested that the tumour was produced by the cells that invaded during the first day, and that the cells remaining in the aggregate were eliminated by the reaction of the host. Before implantation we have pretreated MO4 cell aggregates with 1 microgram/ml of the microtubule inhibitors Nocodazole (ND) and vincristine (VCR), known to inhibit both proliferation and invasion, and with 1 microgram/ml 5-fluorouracil (5-FU), known to inhibit proliferation but not invasion. Tumorigenicity was significantly reduced after treatment with ND or VCR, as compared to treatment with 5-FU or to controls. Histology of pinnae fixed 10 min to 3 days after implantation showed absence or scarceness of invasive MO4 cells after pretreatment with ND or VCR, in contrast with controls or with aggregates pretreated with 5-FU. The effect of ND, VCR and 5-FU on the growth of aggregates in culture on gyrotory shaker was reversible within 1 and 2 days respectively. After treatment with ND or VCR slight alterations in the function of the cytoplasmic microtubule complex remained visible during 3 days in cells migrating from an aggregate explanted on glass. Confrontation of pretreated aggregates with fragments of embryonic chick cardiac muscle in three-dimensional culture indicated that the anti-invasive effect of ND or VCR was reversible in vitro. We concluded that a delay of invasiveness caused by pretreatment with ND or VCR provided the host with the opportunity to eliminate MO4 cells implanted s.c. into the pinna.