Effect of androgen blockade on HER-2 and matrix metalloproteinase-2 expression on bone marrow micrometastasis and stromal cells in men with prostate cancer

The expression of matrix-metalloproteinase-2 in bone marrow micro-metastasis is associated with the presence of circulating prostate cells and a worse prognosis in men treated with radical prostatectomy for prostate cancer

OBJECTIVE

The expression of matrix-metalloproteinase-2 (MMP-2) in the primary tumor is associated with a worse prognosis but little is known at this time regarding the expression in micro-metastasis, the association with circulating prostate cells (CPCs), and outcome.

MATERIAL AND METHODS

This was a prospective study of men undergoing radical prostatectomy. Bone marrow and blood samples were taken at one month after surgery. Micro-metastasis and CPCs were identified using immunocytochemistry with anti-prostate specific-antigen and MMP-2 expression determined with anti-MMP-2. Pathological stage, Gleason score, and time to biochemical failure were recorded; meanwhile, Kaplan-Meier biochemical failure-free survival and restricted mean biochemical failure-free survival times for 10 years were determined.

RESULTS

A total of 282 men participated, 54 (19%) of whom had micro-metastasis but not CPCs (group B) and 88 (31%) of whom had micro-metastasis and CPCs (group C). Men in group C had a higher frequency of MMP-2 expressing micro-metastasis at 63% versus 12% (p<0.001), and MMP-2 expression in bone marrow micro-metastasis was associated with a higher Gleason score (p<0.05) as well as a higher frequency of and shorter time to treatment failure. Also, a 10-year Kaplan-Meier biochemical failure-free survival rate of 0% versus 7.7% (MMP-2 positive versus negative) and a mean time to biochemical failure of 2.6 versus 4.0 years were recorded.

CONCLUSION

The expression of MMP-2 in bone marrow micro-metastasis is associated with a higher Gleason score, the presence of CPCs, and a higher frequency of and shorter time to failure and could be clinically useful for identifying men at high risk of treatment failure.

Angiotensin II promotes the progression of human gastric cancer

The renin-angiotensin system (RAS) plays an important role in cardiovascular homeostasis, carcinogenesis‑related angiogenesis and cell proliferation. The present study was undertaken to determine the expression of angiotensin (Ang) II, Ang II type 1 and 2 receptors (AT1R and AT2R), and the activity of the angiotensin‑converting enzyme (ACE) in gastric cancer tissue. The study further examined the roles of Ang II in the growth of gastric cancer cells in nude mice and in the migration and proliferation of MKN45 human gastric cancer cells. Gastric cancer tissue samples were obtained from gastric cancer patients. The levels of Ang II, AT1R and AT2R, as well as ACE activity were increased in tissues from gastric cancer patients compared to healthy tissues. A gastric cancer model was established by intraperitoneally injecting MKN45 human gastric cancer cells in nude mice, intraperitoneally injecting Ang II and measuring the tumor size every two days. Ang II treatment caused an increase in the size and weight of the tumor mass in nude mice, whereas the AT1R antagonist losartan significantly inhibited the size and weight of the tumor. While Ang II enhanced the migratory and proliferative rate of MKN45 human gastric cancer cells, these were significantly reduced following treatment with losartan. These results indicate that RAS is activated in gastric cancer patients and Ang II promotes the progression of gastric cancer in nude mice, as well as the migration and proliferation of MKN45 human gastric cancer cells.