Potential ability of morphine to inhibit the adhesion, invasion and metastasis of metastatic colon 26-L5 carcinoma cells.

Morphine is frequently used for cancer patient's terminal medical care to relieve cancer pain. In the present study, we examined the inhibitory effect of morphine on experimental lung metastasis and invasion of colon 26-L5 cells. Morphine was found to significantly reduce the number of tumor colonies and the weight of the tumor-containing lung. Morphine inhibited the adhesion and migration of colon 26-L5 cells to extracellular matrix components and invasion into reconstituted basement membrane Matrigel, without affecting the cell proliferation in vitro. Notably, naloxone, an antagonist of morphine, abrogated morphine-induced inhibition of tumor cell adhesion, but did not affect the inhibitory effect on the production of matrix metalloproteinases (MMPs) from tumor cells. These results suggest that morphine inhibited the adhesive and invasive properties of tumor cells by different inhibitory mechanisms that involved the mediation of an opioid receptor.

Increased surgical stress promotes tumor metastasis.

BACKGROUND: Although it is well-known that excessive surgical stress augments the growth of residual cancer and metastasis, whether surgical stress is increased according to the degree of surgical manipulation and can consequently lead to the enhancement of cancer metastasis has not been thoroughly examined. Moreover, the molecules associated with response for stress-enhanced metastasis have not been well-analyzed. The aim of this study was to examine whether cancer metastasis is enhanced with an increase of surgical stress with an experimental lung metastasis model and to analyze the related molecules responsible for stress-enhanced metastasis. METHODS: Colon 26-L5 carcinoma cells (1.5 x 10(4)/mouse) were injected intravenously into 6-week-old female BALB/c mice (Japan SLC, Hamamatsu, Japan). Two hours later, the mice were divided into 5 groups: untreated controls (the C group); mice given anesthesia only (the A group); mice given anesthesia and laparotomy (the AL group); mice given anesthesia, laparotomy, and appendectomy (the ALAp group); and mice given anesthesia, laparotomy, appendectomy, and left hepatic lobectomy (the ALApH group). The anesthesia procedures were the same in all groups (intraperitoneal administration of 0.8 mg/mouse sodium pentobarbital). In the AL, ALAp, and ALApH groups, a 3-cm long laparotomy was performed, and the time of the whole operation was just 5 minutes. All mice were killed 14 days after the procedures, and the number of lung metastases on the lung surface was counted manually. At the same time, BALB/c mice without tumor burden were given the same 5 kinds of surgical stress, and the messenger RNA expression of various metastasis-related molecules in the lung was measured with reverse transcriptase-polymerase chain reaction at 6, 24, and 48 hours after surgical stress. We also examined the effect of ONO-4817 (an inhibitor of matrix metalloproteinases ([MPs]) on lung metastasis in the mice with the 5 kinds of surgical stress. RESULTS: The numbers of lung metastases on the lung surface and the messenger RNA expression of MMP-9, membrane type IBMMP, and urokinase-type plasminogen activator at 24 hours after surgery were enhanced in proportion to the degree of surgical stress. Moreover, ONO-4817 significantly inhibited lung metastasis. CONCLUSION: These results strongly suggest that increased surgical stress augments cancer metastasis via surgical stress-induced expression of proteinases in the target organ of metastasis.

Inhibitory effects of caffeic acid phenethyl ester analogues on experimental lung metastasis of murine colon 26-L5 carcinoma cells.

We have previously examined the antiproliferative activity of caffeic acid phenethyl ester (CAPE) and its 20 analogues against six tumor cell lines, and found that CAPE analogues possess selective antiproliferative activity toward the murine colon 26-L5 carcinoma cell line. To extend our study, the effects of CAPE analogues on the metastatic development of murine colon 26-L5 carcinoma cells in the lung were examined. The oral administration of CAPE (5 mg/mice/d) for 7 d after tumor inoculation decreased the tumor weight and the number of tumor nodules in the lung by 50% and 50%, respectively, compared to the control, while CAPE (5 mg/mice/d) administered for 7 d before tumor inoculation showed no significant effect. Besides CAPE, 4-phenylbutyl caffeate, 8-phenyl-7-octenyl caffeate, 2-cyclohexylethyl caffeate and n-octyl caffeate at an oral dose of 2 mg/mice/d caused a 55%, 43%, 55% and 35% reduction of the tumor nodules in their lung metastasis formation, respectively. These results further elaborate the possibility of CAPE and its analogues to become a new class of chemopreventive agents for the treatment of colon cancer metastasis.

Hepatoprotective effect of majonoside R2, the major saponin from Vietnamese ginseng (Panax vietnamensis).

The hepatoprotective effect of majonoside R 2 (MR2), the major saponin constituent from Vietnamese ginseng ( Panax vietnamensis, Araliaceae), was evaluated in vivo on D-galactosamine ( D-GalN)/lipopolysaccharide (LPS)-induced hepatic apoptosis and subsequent liver failure in mice. Pretreatment of mice with MR2 (50 or 10 mg/kg, intraperitoneal) at 12 and 1 h before D-GalN/LPS injection significantly inhibited apoptosis and suppressed following hepatic necrosis. Importantly, the elevation of serum tumor necrosis factor-alpha (TNF-alpha) level, an important mediator for apoptosis in this model, was significantly inhibited by MR2 at a dose of 50 mg/kg. On the other hand, MR2 was found to protect primary cultured mouse hepatocytes from cell death by inhibiting apoptosis induced by D-GalN/TNF-alpha in vitro, as evidenced by DNA fragmentation analysis. These findings suggested that MR2 may have protected the hepatocytes from apoptosis via an inhibition of TNF-alpha production by activated macrophages and a direct inhibition of apoptosis induced by TNF-alpha.

Antiproliferative activity of Vietnamese medicinal plants.

Methanol, methanol-water (1:1) and water extracts were prepared from seventy-seven Vietnamese medicinal plants and tested for their antiproliferative activities against human HT-1080 fibrosarcoma cells. Among them, fifteen extracts including seven methanol extracts of Caesalpinia sappan, Catharanthus roseus, Coscinium fenestratum, Eurycoma longifolia, Hydnophytum formicarum and Streptocaulon juventas (collected at two areas), six methanol-water (1:1) extracts of Cae. sappan, Cat. roseus, Co. fenestratum, H. formicarum and S. juventas (at two areas), and two water extracts of Cae. sappan and S. juventas exhibited antiproliferative activities in a concentration-dependent manner. Their antiproliferative activities against human cervix HeLa adenocarcinoma, human lung A549 adenocarcinoma, murine colon 26-L5 carcinoma, murine Lewis lung carcinoma (LLC) and murine B16-BL6 melanoma cells were then examined. Co. fenestratum showed selective activity against lung carcinoma and/or lung metastatic cell lines, A549, LLC and B16-BL6, while H. formicarum and S. juventas showed selective activity against human tumor cell lines, HeLa and A549. Characteristic morphological change and DNA fragmentation indicated the antiproliferative activity to be due to the induction of apoptosis.