[Efficacy observation of (125)I seed implantation therapy for locoregional recurrent and metastatic breast cancer]

OBJECTIVE

To assess the efficacy and side effects of (125)I seed implantation for locoregional recurrent and metastatic breast cancer, and to discuss its role in the comprehensive therapy of breast cancer.

METHODS

Forty-three patients with locoregional recurrent or metastatic breast cancer were included in this study. They received (125)I seed implantation and were followed up to evaluate the efficacy and adverse reactions of the treatment.

RESULTS

Among 54 lesions in the 43 cases, there were complete response (CR) in 39, partial response (PR) in 13, stable disease (SD) in 2 patients, with a response rate of 96.3%. All 17 cases with local pain achieved pain relief. With a median follow up of 36 months (range 14 to 60 months), the 1-, 3-, and 5-year local control rate was 85.2%, 53.7% and 1.9%, and the 1-, 3-, and 5-year survival rate was 95.3%, 67.4% and 37.2%, respectively. No serious radiotherapy side effect was observed.

CONCLUSION

In patients with unresectable locoregional recurrent or metastatic breast cancer, (125)I seed implantation shows proved efficacy and few complications, and can be an important treatment option.

eNOS activation and NO function: pregnancy adaptive programming of capacitative entry responses alters nitric oxide (NO) output in vascular endothelium--new insights into eNOS regulation through adaptive cell signaling

In pregnancy, vascular nitric oxide (NO) production is increased in the systemic and more so in the uterine vasculature, thereby supporting maximal perfusion of the uterus. This high level of functionality is matched in the umbilical vein, and in corresponding disease states such as pre-eclampsia, reduced vascular responses are seen in both uterine artery and umbilical vein. In any endothelial cell, NO actually produced by endothelial NO synthase (eNOS) is determined by the maximum capacity of the cell (eNOS expression levels), eNOS phosphorylation state, and the intracellular [Ca(2+)](i) concentration in response to circulating hormones or physical forces. Herein, we discuss how pregnancy-specific reprogramming of NO output is determined as much by pregnancy adaptation of [Ca(2+)](i) signaling responses as it is by eNOS expression and phosphorylation. By examining the changes in [Ca(2+)](i) signaling responses from human hand vein endothelial cells, uterine artery endothelial cells, and human umbilical vein endothelial cells in (where appropriate) nonpregnant, normal pregnant, and pathological pregnant (pre-eclamptic) state, it is clear that pregnancy adaptation of NO output occurs at the level of sustained phase 'capacitative entry' [Ca(2+)](i) response, and the adapted response is lacking in pre-eclamptic pregnancies. Moreover, gap junction function is an essential permissive regulator of the capacitative response and impairment of NO output results from any inhibitor of gap junction function, or capacitative entry using TRPC channels. Identifying these [Ca(2+)](i) signaling mechanisms underlying normal pregnancy adaptation of NO output not only provides novel targets for future treatment of diseases of pregnancy but may also apply to other common forms of hypertension.

Platelet activating factor-induced P-selectin expression in platelets and its related signal transduction

AIM

To study the intracellular signal transduction mechanisms of platelet activating factor (PAF)-induced platelet P-selectin expression.

METHODS

Human blood platelets were used to test the effect of PAF-induced P-selectin expression using flow cytometry.

RESULTS

PAF 20 nmol.L-1 elicited a moderate upregulation of P-selectin expression [(47.5 +/- 1.3)% vs control (3.8 +/- 0.9)%, P < 0.01]. Pretreatment with egtazic acid (EGTA) 2 mmol.L-1 and 5,5'- dimethyl-bis-(o-aminophenoxy)-ethane-N,N,N',N'-tetracetic acid (BAPTA) 200 mumol.L-1 to block Ca2+ influx or chelate the intracellular calcium, respectively, reduced P-selectin expression in response to PAF [(13.3 +/- 0.9)% and (16.8 +/- 1.9)% vs (47.5 +/- 1.3)% of PAF group, P < 0.01]. Inhibition of Na+/H+ exchange with amiloride (Ami) 400 mumol.L-1 resulted in an inhibition of P-selectin expression [(37.5 +/- 2.1)% vs (47.5 +/- 1.3)% of PAF group, P < 0.01]. Genistein (Gen) 300 mumol.L-1 to inhibit protein tyrosine phosphorylation showed similar effect [(29 +/- 4)% vs (47.5 +/- 1.3)% of PAF group, P < 0.01].

CONCLUSION

Multiple signal transduction pathways, including protein tyrosine phosphorylation, Na+/H+ exchange, and Ca2+ mobilization, mediated PAF-induced P-selectin expression.

Inhibition of platelet aggregation by bovine endocardial apyrase

AIM

To study the anti-aggregatory effect of bovine endocardial endothelial cell (EEC)-associated apyrase.

METHODS

Cultured bovine EEC was used. Adenosine diphosphate (ADP) was analyzed by reversed phase HPLC, and rabbit platelet aggregation was measured turbimetrically.

RESULTS

Incubation of EEC with ADP 500 mumol.L-1 resulted in a progressive decrease in ADP concentration, which was paralleled by the decrease in platelet aggregating potential of the unmetabolized ADP. In the presence of aspirin (Asp 1 mmol.L-1)-treated EEC 1 x 10(9) cells.L-1, the aggregation of Asp (1 mmol.L-1) and methylene blue (10 mumol.L-1)-treated platelets in response to thrombin 500 U.L-1 and platelet activating factor (PAF 1 nmol.L-1) was markedly inhibited and was reversible, which was very similar to that in apyrase-treated platelets. The supernatants of EEC had no effect on platelet aggregation. EEC inhibited ADP (5 mumol.L-1)-induced platelet aggregation, but failed to inhibit adenosine 5'-O-(2-thiodiphosphate) (ADP-beta-S, an unmetabolizable structural analog of ADP, 15 mumol.L-1)-induced platelet aggregation.

CONCLUSION

ADP hydrolysis by EEC-associated apyrase is a major anti-thrombotic mechanism of bovine EEC.

Characteristics of apyrase (EC 3.6.1.5) on cultured bovine endocardial endothelial cells

Apyrase activities in some tissues and cells, such as peripheral vascular endothelial cells, have been reported, but these in endocardium endothelial cells have not been reported. The present study was to characterise the properties of bovine endocardium endothelial cells (BEEC)-associated apyrase. Apyrase activity was assayed by inorganic phosphate release, which could be inhibited concentration-dependently by NaN3, an apyrase inhibitor. NaF (20 mmol/L), another inhibitor of apyrase, also markedly inhibited the activity. EDTA or EGTA (1 mmol/L) could also inhibit the activity completely. However, the inhibitor for Na+/K(+)-ATPase, ouabain (3 mmol/L) did not affect the enzyme activity. BEEC apyrase activity was dependent on divalent cations (Ca2+ or Mg2+) and pH value.

Hydrolysis of extracellular adenine nucleotides by cultured bovine endocardial endothelial cells

AIM

To characterize the ATP diphosphohydrolase (apyrase) of bovine endocardial endothelial cells, and to compare ecto-adeninenucleotidase activity between bovine endocardial and aortic endothelial cells (BEEC and BAEC).

METHODS

The nucleotide was analyzed by reversed phase HPLC and apyrase activity was assayed by inorganic phosphate release.

RESULTS

Apyrase inhibitors, both NaN3 10 mmol.L-1 and NaF 20 mmol.L-1, inhibited BEEC apyrase activity by 51% and 38%, respectively. The inhibitor for Na+/K(+)-ATPase, ouabain, did not affect the enzyme activity. Edetic acid 5 mmol.L-1 completely inhibited the enzyme activity. H2O2 0.5 mmol.L-1 downregulated BEEC apyrase activity in a time-dependent manner. The apyrases activities in BAEC were higher than those in BEEC, while the ecto-AMPase activity in BAEC was much weaker than that in BEEC.

CONCLUSION

BEEC have NaN3- and NaF-sensitive, ouabain-insensitive apyrase activity. BEEC had high ecto-AMPase activities, and low apyrases activities as compared with BAEC.

Target selectivity of MAPK phosphorothioate antisense ODN on p42/p44, p38 MAPK, and JNK protein expression and its inhibitory effect on VSMC DNA synthesis

AIM

To analyze the target selective and sequence-specific inhibitory effect of mitogen-activated protein kinase (MAPK) phosphorothioate antisense oligodeoxynucleotides (ODN) on p42/p44, p38 MAPK, c-jun NH2-terminal protein kinases (JNK) protein expression, and DNA synthesis in vascular smooth muscle cell (VSMC).

METHODS

Using a phosphorothioate-protected 17-mer antisense MAPK ODN directed against the initiation of translation sites of the p42/p44 MAPK isoforms by liposomal transfection to deplete cultured rat, rabbit, and fetal calf VSMC MAP kinases. The 17-mer sense and random sequence MAPK ODN were used as controls. After liposomal transfection, cells were exposed to 20% serum for 24 h, and then harvested in lysis buffer. P42/p44, p38 MAPK, and p46/p58 JNK protein expression were measured by Western blot. DNA synthesis was measured by [3H]thymidine incorporation.

RESULTS

Treatment with MAPK antisense ODN (0.1-0.8 mumol.L-1) for 48 h reduced phosphored p42/p44 MAPK protein expression but without effect on p38 MAPK and JNK expression, and inhibited cultured rat, rabbit, and fetal calf VSMC [3H]thymidine incorporation stimulated by 20% serum in a concentration-dependent manner.

CONCLUSION

The MAPK antisense ODN target-selectively and sequence-specifically reduces the p42/p44 MAPK protein expression and concentration-dependently inhibits proliferation of rat, rabbit and fetal calf VSMC.

High glucose enhances mitogenic response to endothelin-1 in rabbit vascular smooth muscle cells

AIM

To examine the effects of high glucose on the mitogenic response of rabbit aortic vascular smooth muscle cells (VSMC) to endothelin-1 (ET-1).

METHODS

VSMC were cultured in normal glucose (5.5 mmol.L-1), high glucose (25 mmol.L-1) or high osmolality (glucose 5.5 mmol.L-1, plus mannitol 19.5 mmol.L-1). DNA synthesis was measured by [3H]thymidine incorporation. The expression of phospho-p44/42 MAPK was determined by Western blot.

RESULTS

At a concentration range from 10(-12) to 10(-8) mol.L-1, ET-1 stimulated [3H]thymidine incorporation and phospho-p44/42 MAPK expression in VSMC in a concentration-dependent manner. From 10(-11) to 10(-8) mol.L-1, the mitogenic effect of ET-1 was higher in VSMC cultured in high glucose at equivalent concentration than cells cultured in normal glucose or high osmolality (P < 0.05 or P < 0.01), but no marked difference was observed in the growth response between cells cultured under the latter two conditions. Similarly, ET-1 increased expression of phospho-p44/42 MAPK by 60%-65% in VSMC cultured in high glucose, compared with cells in normal glucose or high osmolality.

CONCLUSION

VSMC cultured in high glucose exhibited increased mitogenic response to ET-1, which seemed to be related to the enhanced expression of phospho-p44/42 MAPK.

Regulatory role of protein tyrosine phosphorylation in platelet activating factor-induced signal transduction in platelets

AIM

To study the role of protein tyrosine phosphorylation (PTP) in platelet activating factor (PAF)-induced platelet signal transduction cascade.

METHODS

Washed rabbit platelets were used to test the inhibitory effect of genistein (Gen) on platelet aggregation and serotonin secretion. Intracellular Ca2+ ([Ca2+]i) and pH (pHi) were measured by a dual wavelength fluorophotometer with Fura 2-AM and BCECF-AM. PTP was determined with a specific anti-phosphotyrosine monoclonal antibody by Western blotting.

RESULTS

Pretreatment with Gen (100 and 200 mumol.L-1) inhibited PAF (20 nmol.L-1)-stimulated platelet serotonin release by 23.7% +/- 2.0% and 41% +/- 8%, respectively. Similar inhibitory effects of Gen were observed on PAF-evoked increase of [Ca2+]i and intracellular alkalization. PAF also elicited a pronounced increase in PTP of several bands with M(r) 70,000, 60,000, 50,000, 42,000/40,000, and 34,000, which were suppressed markedly by Gen 200 and 400 mumol.L-1. Pretreatment with staurosporine (Sta) 20 nmol.L-1, BAPTA 200 mumol.L-1, and egtazic acid 2 mmol.L-1 to inhibit PKC activation, [Ca2+]i elevation, and Ca2+ influx respectively, also showed an inhibitory effects on the formation of PTP.

CONCLUSION

PTP is involved in multiple signal transduction pathways induced by PAF, on which PKC activation and calcium mobilization play a regulatory role.

Platelet-released ADP stabilizes PAF-induced rabbit platelet aggregation by stabilizing intracellular calcium

AIM

To examine whether platelet-released adenosine diphosphate (ADP) would contribute to the stabilization of rabbit platelet aggregation induced by platelet activating factor (PAF).

METHODS

Rabbit platelet aggregation induced by PAF was measured turbimetrically. ADP release from rabbit platelets stimulated by PAF was determined by HPLC. Intracellular Ca2+ was measured using Ca(2+)-sensitive fluorescent indicator Fura 2-AM.

RESULTS

PAF > or = 1 nmol.L-1 induced full platelet aggregation, which did not deaggregate over 5 min after aggregation reached peak. Platelet aggregation was deaggregated in a concentration-dependent manner by subsequent addition of ADP scavenger ATP-diphosphohydrolase (apyrase) at 5-100 mg.L-1. PAF 3 nmol.L-1 stimulated release of ADP (29% vs 6% of control), and elicited a rapid rise in intracellular calcium ([Ca2+]i) which peaked at approximately 15 s. Then the [Ca2+]i gradually decayed from 585 +/- 80 nmol.L-1 within 100 s to a low level (364 +/- 82 nmol.L-1). Apyrase 100 mg.L-1, added 2 min after PAF, reduced [Ca2+]i to a lower level (171 +/- 29 nmol.L-1).

CONCLUSION

Platelet-released ADP stabilizes PAF-induced rabbit platelet aggregation by stabilizing [Ca2+]i at elevated level.