Inhibition of invasion and metastasis by glypican-3 in a syngeneic breast cancer model

Glypican-3 (GPC3), a proteoglycan bound to the cell membrane through a GPI anchor, is widely expressed in the embryo but down regulated in most adult tissues, with some exceptions as mammary cells. GPC3 is involved in the regulation of cell proliferation and survival in specific cell types. LM3, a murine mammary tumor cell line unable to express GPC3, was stably transfected with the rat GPC3 gene to analyze its role in tumor progression. Upon injection into syngeneic BALB/c mice LM3-GPC3 clones showed less local invasiveness and developed fewer spontaneous and experimental lung metastasis than controls. GPC3-expressing cells were more sensitive to apoptosis induced by serum depletion, exhibited a delay in the first steps of spreading and were less motile than controls. On the other hand, LM3-GPC3 cells were significantly more adherent to FN than control ones. We observed that GPC3 transfectants presented a higher expression of E-cadherin and beta-catenin, molecules whose down regulation has been associated with tumor progression. Exogenous TGF-beta increased MMP-9 activity in both control and GPC3-expressing cells, but did not modulate MMP-2. Contrarily, GPC3 expression prevented the increase of MMP-2 activity induced by IGF-II. Our results suggest that GPC3 has a protective role against mammary cancer progression.

[Comparative study of coronary angioplasty in diabetic patients. Immediate clinical and angiographic results and clinical evolution in the first year of follow up]

BACKGROUND

The success of revascularization procedures for coronary artery disease could be lower in diabetic patients.

AIM

To report the results of coronary angioplasty in diabetic and non diabetic patients.

PATIENTS AND METHODS

All angioplasty procedures performed between 1996 and 1999 were recorded. Demographic data, procedure details, hospital outcome and evolution at one year of follow up were analyzed.

RESULTS

During the study period, 358 patients were treated; of these, 79 were diabetics. Despite the greater severity of coronary lesions among diabetic patients the clinical success of the procedure was 92.4% in diabetics and 91.8% in non diabetics. Hospital mortality was 1.3% in diabetics and 0.7% in non diabetics. Major complications occurred in 3.8% of diabetics and 3.2% in non diabetics. One year survival was 95.9% for diabetics and 98% in non diabetics. There were five late cardiac deaths among non diabetics and 3 among diabetics during the year of follow up. The frequency of new revascularization procedures was 4.3% in diabetics and 8.3% in non diabetics. Event-free survival was 95.6% in diabetics and 89.2% in non diabetics.

CONCLUSIONS

Results of angioplasty were similar in diabetic and non diabetic patients in terms of hospital outcome and late follow-up.

[Acute myocardial infarction caused by total occlusion of the left main coronary artery treated with percutaneous endoluminal revascularization. Clinical case]

We report a 43 years old female who developed an intense precordial pain and arterial hypotension. The patient was admitted to the emergency room in cardiogenic shock. An emergency angiography revealed a total occlusion of the left main coronary artery. An endoluminal coronary angioplasty with the placement of two stents was performed and coronary reperfusion TIMI III was achieved. The patient had a good evolution and one month later, a surgical revascularization was done, to avoid new occlusions. She was discharged in good conditions and in functional capacity I.

[Angioplasty in acute myocardial infarction. Early and late results]

BACKGROUND

The usefulness of angioplasty in the first hours of an acute myocardial infarction is widely demonstrated. However, its long term effects are less well known.

AIM

To report the effects of coronary angioplasty on early and late outcome of patients with acute myocardial infarction.

PATIENTS AND METHODS

A non-randomized, consecutive and retrospective analysis of the hospital and late outcome of 70 patients, aged 35 to 85 years, subjected to coronary angioplasty during an acute myocardial infarction. Patients were followed during 12 to 60 months.

RESULTS

Angioplasty was performed 5.3 +/- 5 hours after the initial symptoms. Anterior descendent artery was occluded in 63% of patients with a 99.5% luminal occlusion and TIMI 0-1 anterograde flow. An angiographic success was achieved in 83% of procedures with a residual stenosis of 32.3%. Recurrent ischemia was observed in 6% of patients, that were treated with a new revascularization procedure. Thirteen percent of patients died, all due to cardiogenic shock. Severe ventricular failure and failure of revascularization influenced mortality. During the first year of follow up there was a 3.3% mortality and 3.3% of patients required a new revascularization procedure. Eighty percent of patients were asymptomatic and event-free.

CONCLUSION

Angioplasty was a useful therapeutic procedure in this group of patients.

[Endovascular stent implantation in the treatment of coronary artery disease: angiographic, and immediate and late clinical results]

BACKGROUND

Coronary revascularization allows a better survival and quality of life in high risk patients with coronary artery disease.

AIM

To report the experience in stent placement as treatment for obstructive atherosclerotic coronary artery disease.

PATIENTS AND METHODS

A prospective analysis of 105 stent placements. A morphological and quantitative analysis of coronary angiograms, using an electronic caliper, was performed. Patients were followed during their hospital stay and after discharge.

RESULTS

In four of 112 coronary lesions, it was not possible to liberate the stent and in 108, it was successfully placed (48 in anterior descending, 19 in circumflex, 36 in right coronary arteries and 5 in saphenous aortocoronary by-pass. Lesions with stent implantation were type A in 11%, B1 in 30%, B2 in 44% and C in 15%. Reference diameter was 3.13 +/- 0.58 mm. After placement, luminal diameter increased from 0.95 +/- 0.43 to 2.99 +/- 0.46 mm, with a final stenosis of 7.2 +/- 10.1%. Angiographic success was obtained in 99% and procedure success in 98%. Hospital mortality was 0.98%. After a mean of eight months follow up, 91% of patients is free of major cardiac events. In 17% angina recurred and 5% required a new revascularization. There were no late cardiac deaths, acute stent thrombosis or infarction in relation to the treated lesion.

CONCLUSIONS

In these patients, stent placement has had excellent immediate and late results.

[Impact of secondary irradiation on operators during coronary arteriography]

BACKGROUND

The activity over cellular genetic pattern of ionizing radiation can produce stochastic and unspecific damages. Interventional cardiology operators have increasing exposure times to ionizing radiation and there is no information about the real protection conferred by simple radiological protection devices.

AIM

To assess the magnitude of secondary ionizing radiation exposure of operators during conventional coronary arteriography, evaluating the radiation exposure during different beam projections and the usefulness of leaded aprons.

MATERIAL AND METHODS

Ionizing radiation received by operators during coronary arteriography was measured using a Geiger-Müller Victoreen model 490 counter. The device was placed in the ventral region, covered by the leaded apron and in the unprotected dorsal region. Radiation was measured in right and left projections during fluoroscopy and shooting.

RESULTS

In right projection, the intensity of ionizing radiation in ventral and dorsal regions was 1.24 +/- 1.1 and 2.9 +/- 4 mR/h respectively (p = 0.08). In left projection, the figures were 2.95 +/- 3 and 7.86 +/- 7.2 mR/h respectively (p = 0.001). During shooting in left projection the radiation exposure in ventral and dorsal regions was 9.66 +/- 6.7 and 32.8 +/- 27 mR/h respectively (p < 0.001). During shooting in right projection that figures were 10.1 +/- 16 and 20.7 +/- 39.8 mR/h respectively (p = 0.09). No correlation between radiation exposure and patients surface area was observed.

CONCLUSIONS

Secondary radiation received by operators is higher during shooting and in left projections. Leaded apron confers a partial protection for ventral region, and great fluctuations in the magnitude of radiation exposure were recorded. Unprotected dorsal region receives a greater amount of radiation in left projections.

Treatment strategies for early-stage chronic lymphocytic leukemia: can interferon-inducible MxA protein and tumor necrosis factor play a role as predictive markers for response to interferon therapy?

The potential benefit of interferon (IFN)-alpha therapy in early-stage B cell chronic lymphocytic leukemia (B-CLL) patients is still under discussion, and no assays are available to distinguish potential responders from nonresponders. Herein we analyzed the usefulness of serum tumor necrosis factor (TNF, a cytokine released by CLL cells) and MxA protein (an intracellular marker for biologic activity of endogenous IFN) concentrations as predictive measurements for evolution and response to IFN therapy in early-stage CLL patients. TNF levels and MxA expression were determined at diagnosis in 21 CLL patients. A statistically significant correlation was found between low TNF levels and MxA expression and between high TNF levels and no measurable MxA expression. The patients were then randomized to receive IFN-alpha or no therapy and were evaluated for response and evolution. When response to IFN-alpha therapy was considered, it became apparent that early-stage CLL patients with higher TNF levels and no measurable MxA expression were more likely to benefit from IFN therapy, whereas those patients with lower TNF levels and MxA expression could be considered CLL candidates for longer survival without therapy. More patients have to be tested to strengthen the value of MxA expression and TNF concentrations for subsequent response to IFN-alpha therapy.

Secretion of gelatinases by human pancreatic cancer cell lines: lack of correlation with invasive ability

Twelve immortalized human cell lines derived from primary or metastatic lesions from pancreatic carcinomas were studied with respect to their in vitro invasiveness and motility. Various levels of invasive capacity and chemotactic responses were found. Zymograms of cells conditioned media were carried out to determine the role of metalloproteinases in pancreatic cancer invasion. No correlations were found, however, between invasive capacity of pancreatic carcinoma cell lines and gelatinase secretion. Putative reasons for these findings are discussed.

Expression of gelatinase/type IV collagenase in tumor necrosis correlates with cell detachment and tumor invasion

We have previously observed that acellular extracts from necrotic areas (NE) of the non-metastatic murine mammary adenocarcinoma M3, enhance in vitro cell detachment and spontaneous lung metastases. In the present study, using different proteinase inhibitors along with NE, only the calcium chelator EDTA could significantly abrogate the enhanced cell detachment from M3 produced by NE. The typical cleavage products of type IV collagenase were detected inside the tumor necrotic area, mainly in association with necrobiotic cells, as evaluated by Western blot analysis and immunohistochemical assays. Zymography revealed the presence of 72- and 92-kDa gelatinase/type IV collagenase in NE. Moreover, NE increased the in vitro invasive ability of cultured M3 cells. The use of specific antibodies against both 72- and 92-kDa type IV collagenases in the invasion assay showed that only the latter was able to revert the enhanced invasiveness to the baseline. It can be concluded that tumor necrosis is an important source of gelatinase/type IV collagenase, mainly in its 92 kDa form, and plays a major role in tumor invasion.