Eicosapentaenoic acid and epidermal growth factor modulation of human breast cancer cell adhesion

Knockdown of Li-cadherin increases metastatic behaviors of LoVo cells

PURPOSE

The aim of this study was to investigate the role of Li-cadherin in invasion and metastasis in LoVo cells.

METHODS

We applied RNA interference mediated downregulation of Li-cadherin expression in LoVo cells. Li-cadherin expression in LoVo cells was examined by semiquantitative polymerase chain reaction, immunofluorescence, western blot, and immunoprecipitation, respectively. Effect of suppression of Li-cadherin expression on cell migration, invasion, and adhesion was detected by wound healing assay, migration assay, invasion assay, and adhesion assay. Expression and activity of MMP-2 and MMP-9 were analyzed by gelatin zymography.

RESULTS

Cell migration, invasion, and adhesion were increased concomitantly with the reduction in Li-cadherin protein expression. Furthermore, downregulation of Li-cadherin expression induced secretion of proMMP-9, active MMP-9 and active MMP-2.

CONCLUSIONS

This study suggests that silencing Li-cadherin has positive actions in the processes of LoVo cells invasion and metastasis, and the interactions among MMP-2, MMP-9, and Li-cadherin participate in the multiple steps of invasion and metastasis in LoVo colorectal cancer cells.

Dietary omega-3-polyunsaturated fatty acids prevent the development of metastases of colon carcinoma in rat liver

BACKGROUND

Fish oil consisting of omega-3 polyunsaturated fatty acids (PUFA) seems to reduce the incidence of colon cancer. The effect of PUFAs on metastasis of colon carcinoma is still unclear.

AIM

The study was designed to examine the effects of a diet rich in omega-3-PUFAs on a model of colorectal metastasis.

METHODS

Thirty animals (WAG/Rij) were randomly assigned to receive an omega-3 diet or a control diet to evaluate their effect on tumor growth. The target male rats (WAG/Rij) were fed a diet containing 15% omega-3-fatty acids three days before and 28 days after intervention and the control rats received 15% coconut oil at the same time points. CC 531 cells, a moderately differentiated colon adenocarcinoma, were injected into the spleen of each rat. After 28 days of diet, animals were sacrificed. The tumor growth was evaluated macroscopically and microscopically in liver tissue. The tissue was examined after immunostaining and the use of monoclonal antibodies.

RESULTS

PUFAs decreased the index of tumor load from 1.54 in the controls to 0.79 in the treatment group (P = 0.036). While 69.2% of the control animals were tumor positive, only 21.4% of the target animals showed tumor after omega-3-fatty acid (P < 0.05).

CONCLUSION

We could show that omega-3-fatty acids may decrease malignant metastatic tumor growth in the liver.