SK18852001A3 - A method for preventing ltbr-mediated activation - Google Patents

Abstract

A method for preventing inflammations, auto-immune diseases and tumoral growth, whereby LTBR-mediated activation is suppressed.

Description

Technical field

The present invention relates to the use of agents that inhibit LTBRs mediated activation for the preparation of cytostatic and inflammatory-inhibiting drugs for the prevention of inflammation, autoimmune diseases and tumor growth.

BACKGROUND OF THE INVENTION

The lymphotoxin-β membrane protein (Browning et al., Cell. Vol. 72, 847-856, 1993) binds in homomeric and heteromeric form to a specific lymphotoxin-β receptor (LTBR) (Crowe et al., Science Vol. 264, 29 April 1994, 707-709).

Browning et al. (J. Exp. Med. Vol. 183, March 1996, 867-878) report that signaling through the LTBR system causes cell death of some adenocarcinoma tumor cells. Therefore, they suggest activation of LTBR as a possible anti-cancer therapy.

Degli-Esposti et al. (Journal of Immunology, 1997, 158, 1756 - 1762) report that melanoma cell growth could be inhibited by activation of the LTBR system. Therefore, they also suggest treatment of solid tumors with lymphotoxin-β.

Conversely, our studies have shown that tumor growth can be slowed or prevented by suppressing LTBR activation.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to use substances that inhibit or at least reduce LTBR-mediated activation for the preparation of cytostatic and inflammatory-inhibiting drugs for the prevention of inflammation, autoimmune diseases and tumor growth.

The use is particularly useful in acute and chronic inflammations such as rheumatoid arthritis or colitis and solid tumors.

The LTBR system can be suppressed at different levels.

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For example, LTBR gene expression can be suppressed using antisense molecules. Another possibility of specifically suppressing LTBR gene expression is to eliminate lymphotoxin-β receptor (LTBR) mRNA, for example, by specific hydrolysis with suitable ribozymes.

Another possibility of suppressing LTBR gene expression is to block the corresponding transcription of signal sequences, for example, the LTBR gene promoter region.

Another possibility to suppress LTBR system activation is to use lymphotoxin-β antagonists, i. molecules that are capable of binding to LTBR but cannot affect any activation of the receptor system. Such agents can be found by screening the agents to be tested in the cellular assay system for their ability to reduce LTBR system activation in the presence of the addition of lymphotoxin-β.

Suppression of LTBR activation has been observed to inhibit tumor angiogenesis while showing an inhibitory effect on solid tumor growth.

Therefore, prevention of LTBR activation using the above agents is particularly useful for inhibiting tumor angiogenesis.

The following examples illustrate the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The figures show photographs of control tumors (upper part) and tumors transfected with the β1 -receptor inhibitor (lower part) on day 2 (Figure 2) and on day 9 (Figure 3) after tumor cell administration.

DETAILED DESCRIPTION OF THE INVENTION

Example 1

Tumor cells (BFS-1) were transfected with the LTBR fusion protein and immunoglobulin (BFS-LTR). This LTBR fusion protein and immunoglobulin acted as an LTBR inhibitor. Compared to wild type tumor cells, these

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-3transfected tumor cells showed inhibited tumor growth when introduced into syngeneic mice (Figure).

Example 2

If, in a second experiment, these tumor cells were introduced into ligand-deficient mice (i.e., double-knockout mice that do not produce either lymphotoxin-alpha or lymphotoxin-beta), no significant differences in tumor growth of the transfected tumor cells were found to be higher than in a wild-type tumor cell (Figure).

Example 3

Observation of tumor growth in mice by intravital microscopy

Normal tumor cells or tumor cells that were transfected with an LTβ receptor inhibitor (BSF-1-LT3R-IG: Fc) or a control plasmid (p55TNF receptor-Ig: Fc) were injected subcutaneously into mice (C57BL / 6) into the cutaneous skin. tumor growth or angiogenesis was examined by intravital microscopy. The development of edema on the second day after tumor cell administration was already significantly less in animals receiving transfected LTβ-receptor inhibitor tumor cells than in control. While normal tumor cells and tumor cells transfected with a control construct induced significant angiogenesis after five to nine days and then grew similarly to tumors, no angionogenesis in the tumor area and surrounding skin areas was observed in tumors transfected with an LTβ-receptor inhibitor. These tumors will no longer grow further.

Claims (9)

PATENT CLAIMS Use of agents that inhibit LTBR-mediated activation for the preparation of cytostatic and inflammatory-inhibiting drugs for the prevention of inflammation, autoimmune diseases and tumor growth. Use according to claim 1, wherein the expression of the LTBR gene is suppressed. Use according to claim 2, wherein LTBR nonsense molecules are used. The use of claim 2, wherein the LTBR mRNA is specifically hydrolyzed. The use of claim 2, wherein the LTBR transcription signal sequences are specifically blocked. The use of claim 2, wherein the transcription factors affecting LTBR transcription signal sequences are specifically blocked. Use according to claim 1, wherein LTBR antagonists are used. The use of claim 1, wherein the endogenous LTBR ligands are captured. Use according to claim 1 for inhibiting angiogenesis of tumors.