[Studying the tumor growth inhibitory effect of modified GnRH-III-anthracycline bioconjugates in subcutaneous vs. orthotopic models in vivo].

Targeted tumor therapy is a perspective procedure to specifically destroy the cancer tissues with eliminating or at least decreasing the side effects of anticancer drugs. For this purpose the drug molecule is attached to a targeting moiety (e.g.

A mixture of amino acids and other small molecules present in the serum suppresses the growth of murine and human tumors in vivo.

Previously we have hypothesized that the small molecules which are selectively accumulated in cancer cells might participate in a non-immunological antitumor surveillance mechanism. We demonstrated earlier that a mixture of experimentally selected substances ("active mixture", AM: L-arginine, L-histidine, L-methionine, L-phenylalanine, L-tyrosine, L-tryptophan, L-ascorbate, D-biotin, pyridoxine, riboflavin, adenine, L(-)malate) possesses a selective toxic effect in vitro on a variety of tumor cell lines, and we have shown that the AM selectively induces apoptosis of cancer cells in vitro. To explore the in vivo significance of our earlier findings we examined the antitumor effect of AM in Colon 26 murine colorectal adenocarcinoma, B16 murine melanoma, MXT murine mammary carcinoma, S180 murine sarcoma, P388 murine lymphoid leukemia, HL-60 human promyeloid leukemia, PC-3 human prostate carcinoma, and HT-29 human colon carcinoma tumor models.

The effect of regular exercise on development of sarcoma tumor and oxidative damage in mice liver.

Regular exercise has the capability of decreasing the incidence and progress of certain cancers. Murine sarcoma, (S-180) cells were transplanted to control (TC), exercise trained (10 week, 1 hour day, 5 times/ week) mice, which had the swimming training terminated at the time of transplantation (ETT), and also to a group of mice that continued to exercise during tumor bearing (ETC). Continuous exercise decreased the size of tumor by about 50%.

Development of an oxime bond containing daunorubicin-gonadotropin-releasing hormone-III conjugate as a potential anticancer drug.

Here, we report on the synthesis and biological properties of a conjugate in which daunorubicin (Dau) as chemotherapeutic agent was attached through an oxime bond to gonadotropin-releasing hormone-III (GnRH-III) as targeting moiety. In vitro toxicity and the cytostatic effect of the conjugate on MCF-7 human breast and C26 murine colon cancer cell lines were determined, and the results were compared with those obtained for the free daunorubicin, as well as with the doxorubicin containing derivative. In vivo antitumor effect of daunorubicin-GnRH-III was studied on Balb/c female mice transplanted with C26 tumor.

Synthesis, conformation, and immunoreactivity of new carrier molecules based on repeated tuftsin-like sequence.

Sequential oligopeptides based on a pentapeptide (TKPKG) derived from tuftsin with different lengths were synthesized by stepwise solid phase methodology. These highly soluble oligomers were nontoxic on mouse spleen cells, and other biological data suggested that tuftsin-like properties were also presented. The (TKPKG)n (n=2,4,6,8) oligopeptides were not immunogenic; however, they increased sheep red blood cells (SRBC) antigen specific antibody response in mice, demonstrating their immunostimulatory effect.

Drug targeting by macromolecules without recognition unit?

his review will summarize available information on the ability of macromolecular conjugates containing no specific recognition motifs to deliver anthracyclines (daunomycin, adriamycin) or methotrexate to target cells such as tumour cells or macrophages. Conjugates with natural (proteins, DNA, carbohydrates) and synthetic macromolecules (linear and branched chain poly-alpha-amino acids, non-biodegradable DIVEMA, HPMA etc.) will be reviewed.

The antitumour effect of the somatostatin analogue TT-232 depends on the treatment regimen.

The somatostatin analogue TT-232, containing a five residue ring structure, has a strong antitumour activity both in vitro and in vivo. This peptide has no effect on growth hormone (GH) release, but exhibits a remarkable tyrosine kinase inhibitory effect and induced apoptosis. We studied the effect of TT-232 in different routes of administration and treatment schedules on various types of mouse tumour models.

Attenuation of the development of murine solid leukemia tumor by physical exercise.

The active involvement of physical exercise in the evolution of a variety of cancers is well documented. However, its role in solid leukemia tumor development is essentially unknown. Solid leukemia tumor cells were transplanted into 21 hybrid BDF1 control mice, exercise-trained mice that did not exercise during leukemia and exercise-trained mice that exercised during leukemia.