Effect of Wf-536, a novel ROCK inhibitor, against metastasis of B16 melanoma.
OBJECTIVE
Rho-associated coiled-coil-forming protein kinase (ROCK) is pivotally involved in invasion by tumor cells and their evolution to metastasis. We have developed a novel inhibitor of ROCK, Wf-536 [(+)-(R)-4-(1-aminoethyl)-N-(4-pyridyl) benzamide monohydrochloride]. In the present study, we investigated its effect on in vitro invasion and in vivo pulmonary metastasis of B16 melanoma.


METHODS
The following were evaluated: the anti-invasive effect of Wf-536 against the motility of mouse B16BL6 melanoma cells through a culture insert layered with reconstituted basement membrane (Matrigel); the cytotoxic effect of Wf-536 in the same cell line; the antimetastatic effect of Wf-536, administered by osmotic pump, on spontaneous pulmonary metastasis following subcutaneous injection of B16BL6 melanoma in mice; and the inhibitory effect of orally administered Wf-536, alone or in combination with the antineoplastic drug paclitaxel, on pulmonary metastasis of intravenously injected B16F10 melanoma in mice.


RESULTS
Wf-536 inhibited in vitro invasion by B16BL6 cells significantly and in a concentration-dependent manner and displayed an anti-invasive effect under conditions of both chemotaxis and chemokinesis. No cytotoxic effect was observed at any of the concentrations used. In vivo, Wf-536 administration suppressed tumor colony formation on the lung surface in a dose-dependent manner (0.3-3 mg/kg per day), with a metastasis inhibition rate of 95% at 3 mg/kg per day. In experimental metastasis of B16F10 melanoma, oral administration of Wf-536 significantly decreased tumor colony formation in the lung, with an inhibition rate of 41% at 3 mg/kg per day. The inhibition rate of paclitaxel (5 mg/kg per day) was 27%. The combination of Wf-536 and paclitaxel produced a synergistic effect on B16F10 metastasis and a 68% inhibition rate. Wf-536 administration at the doses used did not alter body weight, blood pressure or the health of treated animals as compared to vehicle-treated controls.


CONCLUSIONS
The results suggest that Wf-536 is a potentially valuable drug for preventing tumor metastasis both in monotherapy and in combination with an antineoplastic drug.
Nakajima
Masahide
M
Pharmaceuticals Research Unit, Mitsubishi Pharma Corporation, 1000, Kamoshida-cho, Aoba-ku, 227-0033 Yokohama, Japan. Nakajima.Masahide@mh.m-pharma.co.jp
Hayashi
Kazutaka
K
Egi
Yasuhiro
Y
Katayama
Ken-ichi
K
Amano
Yusaku
Y
Uehata
Masayoshi
M
Ohtsuki
Makio
M
Fujii
Akihiro
A
Oshita
Koh-ichi
K
Kataoka
Hirotoshi
H
Chiba
Kenji
K
Goto
Nobuharu
N
Kondo
Takao
T
D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology*; D000972:Antineoplastic Agents, Phytogenic / Q000627:therapeutic use; D001549:Benzamides / Q000494:pharmacology*; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D047908:Intracellular Signaling Peptides and Proteins; D008175:Lung Neoplasms / Q000188:drug therapy* / Q000556:secondary*; D008546:Melanoma, Experimental / Q000188:drug therapy* / Q000473:pathology*; D051379:Mice; D009361:Neoplasm Invasiveness / Q000517:prevention & control; D017239:Paclitaxel / Q000627:therapeutic use; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors*; D011725:Pyridines / Q000494:pharmacology*; D054460:rho-Associated Kinases
D000970:Antineoplastic Agents; D000972:Antineoplastic Agents, Phytogenic; D001549:Benzamides; D004791:Enzyme Inhibitors; D047908:Intracellular Signaling Peptides and Proteins; D011725:Pyridines; C460080:Y 32885; D017346:Protein Serine-Threonine Kinases; D054460:rho-Associated Kinases; D017239:Paclitaxel