Retrospective Proteomic Analysis of a Novel, Cancer Metastasis-Promoting RGD-Containing Peptide.

Patients who undergo surgical extirpation of a primary liver carcinoma followed by radiotherapy and chemotherapy leading to complete remission are nevertheless known to develop cancerous metastases 3-10 years later. We retrospectively examined the blood sera collected over 8 years from 30 patients who developed bone metastases after the complete remission of liver cancer to identify serum proteins showing differential expression compared to patients without remission. We detected a novel RGD (Arg-Gly-Asp)-containing peptide derived from the C-terminal portion of fibrinogen in the sera of metastatic patients that appeared to control the EMT (epithelial-mesenchymal transition) of cancer cells, in a process associated with miR-199a-3p. The RGD peptide enhanced new blood vessel growth and increased vascular endothelial growth factor levels when introduced into fertilized chicken eggs. The purpose of this study was to enable early detection of metastatic cancer cells using the novel RGD peptide as a biomarker, and thereby develop new drugs for the treatment of metastatic cancer.

Tricin inhibits proliferation of human hepatic stellate cells in vitro by blocking tyrosine phosphorylation of PDGF receptor and its signaling pathways.

4',5,7-Trihydroxy-3',5'-dimethoxyflavone (Tricin), a naturally occurring flavone, has anti-inflammatory potential and exhibits diverse biological activities including antigrowth activity in several human cancer cell lines and cancer chemopreventive effects in the gastrointestinal tract of mice. The present study aimed to investigate the biological actions of tricin on hepatic stellate cells (HSCs) in vitro, exploring its potential as a treatment of liver fibrosis, since HSC proliferation is closely related to the progression of hepatic fibrogenesis in chronic liver diseases leading to irreversible liver cirrhosis and hepatocellular carcinoma. Tricin inhibited platelet-derived growth factor (PDGF)-BB-induced cell proliferation by blocking cell cycle progression and cell migration in the human HSC line LI90 and culture-activated HSCs. It also reduced the phosphorylation of PDGF receptor ß and the downstream signaling molecules ERK1/2 and Akt, which might be due to its tyrosine kinase inhibitor properties rather than inhibition of the direct binding between PDGF-BB and its receptor. Our findings suggest that tricin might be beneficial in HSC-targeting therapeutic or chemopreventive applications for hepatic fibrosis.

Esophagectomy with extended lymphadenectomy for submucosal esophageal cancer: long-term outcomes and prognostic factors.

BACKGROUND: There are controversies regarding the extent of lymphadenectomy necessary during the course of esophagectomy for submucosal esophageal cancer. The purpose of this study was to examine the long-term outcomes after esophagectomy with extended lymphadenectomy in patients with submucosal esophageal cancer and to investigate the prognostic factors in these patients. MATERIALS: A prospectively maintained database identified 105 previously untreated patients with submucosal esophageal cancer who underwent transthoracic esophagectomy with three-field or two-field lymphadenectomy. Median follow-up was 101 months. RESULTS: All patients received R0 resection. Ninety-eight patients had squamous cell carcinoma, and seven had adenocarcinoma. Lymph node metastasis was present in 38 patients (36.2%), of whom 9 patients (23.7%) had positive cervical nodes. Thirty-five patients (33.3%) had other primary malignancies. The overall 5- and 10-year survival rates were 74.4 and 57.4%, respectively. The cause of death was recurrent disease in 16 patients, other malignancy in 12, and noncancer-related disease in 18. Univariate analyses demonstrated that other primary malignancy (P = 0.0041), poor differentiation (P = 0.0203), and angiolymphatic invasion (P = 0.0347) significantly affected overall survival. There was no difference in survival between patients with lymph node metastasis and those without (P = 0.9809). Multivariate analysis found other primary malignancy to be the only independent prognostic factor (hazards ratio, 2.295; 95% confidence interval, 1.201-4.386; P = 0.0119). CONCLUSIONS: Esophagectomy with extended lymphadenectomy for submucosal esophageal cancer results in 57.4% survival at 10 years. Other primary malignancy is the only independent predictor affecting long-term survival. Patients should be examined rigorously for other primary malignancy as well as recurrent disease during long-term follow-up.

Factors related to an early restoration of exercise capacity after major lung resection.

PURPOSE: We attempted to identify the factors related to an early restoration of the exercise capacity after lung resection. METHODS: Major lung resection was performed in 164 patients. Exercise testing and spirometry were performed before surgery, and 2 weeks and 1 month afterward. During exercise, the maximum oxygen uptake per minute per m(2) of body surface area (VO(2)max/m(2)) was measured. The percent change of VO(2)max/m(2) at 2 weeks and 1 month after surgery was calculated by setting the preoperative VO(2)max/m(2) value as 100%. Patients were then assigned to the early restoration group or late restoration group according to their VO(2)max/m(2) measured 2 weeks after surgery. Preoperative cardiopulmonary function, as well as various preoperative and intraoperative factors were compared between the two groups. RESULTS: At 2 weeks after surgery, the mean VO(2)max/m(2) was 80.9% compared with that before surgery, and was 88.1% at 1 month. A multivariate analysis showed that the surgical method used (thoracotomy and mediastinal lymph node dissection) had a significant effect on the postoperative restoration of the VO(2)max/m(2). CONCLUSION: An early restoration of exercise capacity after lung resection is possible in patients without mediastinal lymph node dissection and in those who have a small thoracotomy wound.

Selection of pulmonary resection procedures to reduce postoperative complications in 200 patients.

PURPOSE: We previously demonstrated in a pilot study that postoperative cardiopulmonary complications could be reduced by selecting pulmonary resection procedures based on the results of a combination of specific preoperative cardiopulmonary function tests. The present study reports a re-examination of the criteria for preoperative screening and prospectively assessed whether the selected surgical procedures were appropriate in 200 patients who underwent the planned extent of pulmonary resection. METHODS: In 200 patients requiring lung tumor resection, five preoperative parameters (forced expiratory volume in 1 s on the intact side, maximal oxygen uptake, ejection fraction, occluded pulmonary artery pressure, and occluded total pulmonary vascular resistance index) were used to assign each patient to one of five risk categories in order to select the optimal resection procedure. Thereafter, the postoperative course was investigated to determine the value of this selection method. RESULTS: Thoracotomy was performed in 195 of the 200 patients (97.5%). Two patients (1%) died; one patient succumbed to acute exacerbation of interstitial pneumonia and the other patient died from pulmonary embolism. Six patients (3.1%) developed major complications after surgery and 12 patients (6.2%) had mild complications, while 175 (89.7%) showed a good postoperative course. CONCLUSION: The use of five preoperative parameters to select the pulmonary resection procedure minimized postoperative death and major complications.

N-myc downstream-regulated gene 1 (NDRG1) a differentiation marker of human breast cancer.

N-myc downstream-regulated gene 1 (NDRG1), also called differentiation-related gene-1 (Drg1) and Cap43, is expressed in various normal tissues and suppressed in several malignancies. In this study, whether NDRG1 expression was correlated with differentiation of human breast cancer cells has been investigated. Endogenous expression level of NDRG1 was closely correlated with differentiation status of breast cancer cell lines. Furthermore, sodium butyrate (NaB), an inducer of cellular differentiation, increased the expression of ß-casein, a milk-related differentiation marker, together with up-regulation of NDRG1 in breast cancer cells. In contrast, inhibition of NDRG1 by its siRNA resulted in reduced accumulation of ß-casein. Immunohistochemical analysis showed co-expression of NDRG1 and ß-casein or milk fat protein (MFP), another differentiation marker of breast tissue, in the mouse xenograft model of breast cancer. Furthermore, overexpression of NDRG1 expanded the differentiated area in the xenograft model of breast cancer. In human breast cancer, using samples from 45 patients, we also showed close relationship between NDRG1 and ß-casein or MFP expression. Altogether, in vitro and in vivo data demonstrated a possible role of NDRG1 in differentiation of breast cancer. We concluded that NDRG1 could be used as a biomarker for differentiation of breast cancer for both diagnostic and therapeutic purposes.

Photodynamic therapy for large superficial squamous cell carcinoma of the esophagus.

BACKGROUND: Photodynamic therapy (PDT) has been found to be safe and effective in patients with small early esophageal squamous cell carcinoma (SCC). However, its efficacy for widespread superficial SCC has not yet been confirmed. OBJECTIVE: To assess the long-term survival, complications, and recurrence of PDT for large superficial esophageal SCC. DESIGN: Retrospective study. SETTING: Tertiary referral center. PATIENTS: A total of 38 patients with superficial SCC of the esophagus. All patients had a large unifocal lesion or multifocal lesions that were too large to be resected endoscopically. In addition, all patients were physiologically unfit for esophagectomy or had refused surgery. INTERVENTIONS: PDT with porfimer sodium. MAIN OUTCOME MEASUREMENTS: Clinical follow-up, long-term survival, complications, and recurrence were evaluated. RESULTS: Thirty-one patients (82%) had mucosal cancer (T1m), and 7 (18%) had submucosal cancer (T1sm). No patient had lymph node involvement. Nineteen patients had other primary malignancies. Complete remission was achieved in 33 (87%). At the time of writing, 28 patients (74%) were alive without recurrence. After a median follow-up period of 64 months (range, 7-125 months) after PDT, the overall 5-year survival rate was 76%. There was no treatment-related mortality. LIMITATIONS: Retrospective study with a small number of patients. CONCLUSIONS: This long-term follow-up study revealed that PDT was a potentially curative treatment for large superficial esophageal SCC. PDT might be a reasonable alternative to esophagectomy or to endoscopic resection for patients with superficial SCC of the esophagus without lymph node metastasis.

Bortezomib sensitizes human esophageal squamous cell carcinoma cells to TRAIL-mediated apoptosis via activation of both extrinsic and intrinsic apoptosis pathways.

Esophageal squamous cell carcinoma (ESCC) is one of the most aggressive human cancers, and novel treatment modalities are required. We investigated the therapeutic potential of the tumor necrosis factor-related apoptosis-inducing ligand (TRAIL/Apo2L) in combination with the proteasome inhibitor bortezomib (Velcade) on human ESCC cell lines. Bortezomib enhanced the susceptibility to TRAIL in 12 of the 15 ESCC cell lines tested, although most showed low sensitivity to TRAIL as a single agent. The enhancement of TRAIL-induced apoptosis by bortezomib was caspase dependent. Increased processing of caspase-8 often accompanied enhancement of TRAIL-induced apoptosis by bortezomib. However, the increased cell surface expression of death receptors observed on bortezomib treatment did not seem to be crucial for this effect. For some ESCC, bortezomib treatment resulted in a more efficient recruitment of caspase-8 and the Fas-associated death domain to the death-inducing signaling complex. Additional downregulation of the cellular FLICE-inhibitory protein long isoform [c-FLIP(L)] could cooperate in the activation of the extrinsic pathway in some cases. For other ESCC, the crucial effect of bortezomib treatment seemed to be increased signaling via the intrinsic apoptotic pathway on subsequent exposure to TRAIL. Thus, bortezomib could sensitize ESCC to TRAIL apoptosis by multiple molecular mechanisms of action. Therefore, the combination of bortezomib and TRAIL might be a novel therapeutic strategy for ESCC patients who fail to respond to standard chemoradiotherapy that predominantly targets the mitochondrial apoptotic pathway.

A phase II trial of chemoradiotherapy for stage I esophageal squamous cell carcinoma: Japan Clinical Oncology Group Study (JCOG9708).

OBJECTIVE: The study objective was to evaluate the efficacy and toxicity of chemoradiotherapy with 5-fluorouracil (5-FU) plus cisplatin in patients with Stage I esophageal squamous cell carcinoma (ESCC). The primary endpoint was proportion of complete response (%CR). METHODS: Patients with Stage I (T1N0M0) ESCC, aged 20-75 years, without indication of endoscopic mucosal resection were eligible. Treatment consisted of cisplatin 70 mg/m(2) (day 1) and 5-FU 700 mg/m(2)/day (days 1-4) combined with 30 Gy radiotherapy (2 Gy/day, 5 days/week, days 1-21). The cycle was repeated twice with 1-week split. Salvage surgery was recommended for residual tumor or local recurrence. RESULTS: From December 1997 to June 2000, 72 patients were enrolled. No ineligible patient or major protocol violation was observed. There were 63 CRs for %CR of 87.5% [95% confidence interval (CI): 77.6-94.1]. Six patients with residual tumor successfully underwent esophagectomy. There was no Grade 4 toxicity. Four-year survival proportion was 80.5% (95% CI: 71.3-89.7), and 4-year major relapse-free survival proportion was 68% (95% CI: 57.3-78.8) (mucosal recurrence removed by endoscopy was not counted as an event). CONCLUSIONS: High CR proportion and survival proportion with mild toxicity suggest that this regimen could be considered as a candidate of new standard treatment to be compared with surgery in patients with Stage I ESCC.

Retrospective investigation of pulmonary resection in patients with high total pulmonary vascular resistance during preoperative unilateral pulmonary artery occlusion.

PURPOSE: The aim of this study was to evaluate the indications for pulmonary resection (lobectomy) in patients with increased total pulmonary vascular resistance (TPVR) during a preoperative unilateral pulmonary artery occlusion (UPAO) test. According to our previous report, the feasibility of performing lobectomy in patients with a high risk of cardiopulmonary complications is determined on the basis of the increase in TPVR after 15 min of obstruction during the UPAO test (occluded TPVR). METHODS: A total of 19 high-risk [occluded TPVR > or =700 dynes/s/cm(-5)/m(2) (dynes)] patients who underwent lobectomy or pneumonectomy were studied and a detailed analysis of postoperative cardiopulmonary complications was performed. The subjects were divided into four groups based on the occluded TPVR (700-799 dynes, 800-899 dynes, 900-999 dynes, or > or =1000 dynes) to compare the incidence of postoperative complications. RESULTS: Two patients died after surgery. One of them had an occluded TPVR >1000 dynes and died 313 days after right upper lobectomy; the other had an occluded TPVR of 783 dynes and died 20 days after right pneumonectomy. Postoperative cardiopulmonary complications occurred in 6 of 19 patients (31.6%), and all three patients with an occluded TPVR > or =900 dynes developed cardiopulmonary complications. CONCLUSION: Limited surgery should be performed in patients with an occluded TPVR > or =900 dynes.

Expression of HER2 and estrogen receptor alpha depends upon nuclear localization of Y-box binding protein-1 in human breast cancers.

In our present study, we examined whether nuclear localization of Y-box binding protein-1 (YB-1) is associated with the expression of epidermal growth factor receptors (EGFR), hormone receptors, and other molecules affecting breast cancer prognosis. The expression of nuclear YB-1, clinicopathologic findings, and molecular markers [EGFR, HER2, estrogen receptor (ER)alpha, ER beta, progesterone receptor, chemokine (C-X-C motif) receptor 4 (CXCR4), phosphorylated Akt, and major vault protein/lung resistance protein] were immunohistochemically analyzed. The association of the expression of nuclear YB-1 and the molecular markers was examined in breast cancer cell lines using microarrays, quantitative real-time PCR, and Western blot analyses. Knockdown of YB-1 with siRNA significantly reduced EGFR, HER2, and ER alpha expression in ER alpha-positive, but not ER alpha-negative, breast cancer cell lines. Nuclear YB-1 expression was positively correlated with HER2 (P = 0.0153) and negatively correlated with ER alpha (P = 0.0122) and CXCR4 (P = 0.0166) in human breast cancer clinical specimens but was not correlated with EGFR expression. Nuclear YB-1 expression was an independent prognostic factor for overall (P = 0.0139) and progression-free (P = 0.0280) survival. In conclusion, nuclear YB-1 expression might be essential for the acquisition of malignant characteristics via HER2-Akt-dependent pathways in breast cancer patients. The nuclear localization of YB-1 could be an important therapeutic target against not only multidrug resistance but also tumor growth dependent on HER2 and ER alpha.

Antiviral activities of heated dolomite powder.

The effect of the heating conditions of dolomite powder on its antiviral activity was studied against the H5N3 avian influenza virus. Calcium oxide (CaO) and magnesium oxide (MgO), obtained by the thermal decomposition of dolomite above 800 degrees C, were shown to have strong antiviral activity, but the effect was lessened when the heating temperature exceeded 1400 degrees C. Simultaneous measurement of the crystallite size suggested that the weakening of the activity was due to the considerable grain growth of the oxides. It was found that the presence of Mg in dolomite contributed to the deterrence of grain growth of the oxides during the heating process. Although both CaO and MgO exhibited strong antiviral activity, CaO had the stronger activity but quickly hydrated in the presence of water. On the other hand, the hydration of MgO took place gradually under the same conditions. Separate measurements using MgO and Mg(OH)2 revealed that MgO had a higher antiviral effect than Mg(OH)2. From the overall experiments, it was suggested that the strong antiviral activity of dolomite was related to the hydration reaction of CaO.

Long-term recovery of exercise capacity and pulmonary function after lobectomy.

OBJECTIVE: The objective of the present study was to perform longitudinal objective evaluations of recovery of exercise capacity based on expired gas analysis during exercise testing up to 1 year after pulmonary resection. METHODS: The study included 18 patients who underwent lobectomy. Expired gas analysis during exercise testing was conducted 1 week before surgery and 2 weeks, 1 month, 3 months, 6 months, and 1 year after surgery. The parameters studied included maximum exercise capacity based on expired gas analysis during exercise testing (maximum oxygen uptake per minute per square meter of body surface area) and assessment of moderate exercise capacity (anaerobic threshold per square meter of body surface area). The changes in postoperative data relative to the preoperative values (baseline) were assessed, including the percent changes from baseline data, which were arbitrarily given a value of 100. RESULTS: Maximum oxygen uptake per minute per square meter of body surface area decreased significantly to 78.6% +/- 14.2% of the baseline value at 2 weeks after surgery and was 80.3% +/- 12.7%, 90.9% +/- 15.9%, 90% +/- 19.7%, and 97% +/- 4.8% of the baseline value at 1, 3, and 6 months, and 1 year, respectively. Anaerobic threshold per square meter of body surface area reached 91.1% +/- 17.5% of the baseline value even 2 weeks after surgery and was 87.1% +/- 17.3%, 97.5% +/- 28.0%, 84.3% +/- 13.2%, and 104% +/- 16.2% of the baseline value at 1, 3, and 6 months, and 1 year, respectively. CONCLUSION: The extent of recovery of exercise capacity at 1 year after surgery was approximately 95%. Furthermore, the anaerobic threshold per square meter of body surface area was restored to the preoperative level by 1 year after surgery.

Second-line combination chemotherapy with docetaxel for cisplatin-pretreated refractory metastatic esophageal cancer: a preliminary report of initial experience.

BACKGROUND AND AIMS: Patients with esophageal cancer often develop metastatic disease after esophageal resection and generally receive cisplatin-based chemotherapy or chemoradiotherapy. The efficacy and toxicity of the combination of docetaxel, 5-fluorouracil (5-FU) and cisplatin (DFC) as a second-line chemotherapy were evaluated in patients with postoperative metastatic esophageal cancer refractory to cisplatin-based chemotherapy. PATIENTS AND METHODS: Twenty patients with metastatic esophageal cancer after esophagectomy refractory to cisplatin-based therapy were included in this study. The DFC regimen consisted of docetaxel (60 mg/m(2)) on day 1, 5-FU (500 mg/day) on days 1-5 and cisplatin (10 mg/day) on days 1-5, being repeated every 3 weeks. RESULTS: A total of 49 cycles (median 2, range 1-6) was administered to 20 patients. The median follow-up was 8 months (range 3-24). Of the 20 patients, 1 had a complete response, 6 had a partial response, 6 had stable and 7 had progressive disease. Median time to progression for all patients was 4 months (95% Cl 1.7-5.6). The median overall survival for all patients was 8 months (95% CI 5.7-10.3). The major toxicity was myelosuppression. Neutropenia of grade 3 or more occurred in 13 patients (65%), and thrombocytopenia of grade 3 occurred in 1 patient (5%). Febrile neutropenia was observed in 1 patient (5%). There was no treatment-related mortality. CONCLUSION: DFC is a feasible and promising regimen as a second-line therapy in metastatic/recurrent esophageal cancer refractory to cisplatin-based chemotherapy.

Strong antiviral activity of heated and hydrated dolomite--preliminary investigation.

Heated and hydrated naturally occurring dolomite showed very strong antiviral activity. Infectivity of avian and human influenza, avian infectious bronchitis (coronavirus), Newcastle disease (paramyxovirus) and avian laryngotracheitis (herpesvirus) viruses dropped at least 1,000 fold following contact with the dolomite for five minutes at 4 degrees C. Dolomite is expected to be useful to inhibit the incidence of emerging and re-emerging infectious diseases.

Selection of pulmonary resection procedures to avoid postoperative complications.

PURPOSE: We previously found a potential predictive value in a retrospective analysis of spirometry and an expired gas analysis during the exercise. We sought to reduce postoperative cardiopulmonary complications by selecting lung tumor resection procedures based on a combination of specific preoperative cardiopulmonary function test results. METHODS: Out of the 53 patients requiring a lung tumor resection, five preoperative parameters (forced expiratory volume in 1 s for intact-side, maximal oxygen uptake, ejection fraction, occluded pulmonary artery pressure, and occluded total pulmonary vascular resistant index) were used to assign patients to one of five risk categories in order to select the optimal pulmonary resection procedure. The patients were later grouped according to their postoperative course to test the value of this procedure selection method. RESULTS: No patient died or developed severe complications after surgery. Five patients had mild complications, while 46 had a good postoperative course; the 13 deaths, in the cancer cases, included 11 from primary or metastatic cancer and 2 from other causes. The overall five-year survival was 61.4%. CONCLUSION: This method for determining a pulmonary resection procedure avoided postoperative deaths and severe cardiopulmonary complications, while achieving a good outcome.

[Conventional chemotherapy combined with the repetitive immune cell transfer for patients with refractory advanced gastric cancer].

In order to take advantage by both the anticancer effects and reconstruction of antitumor immunity, we compared the feasibility of a combination of CTL transfer and chemotherapy (ChT) for patients (pts) with malignant ascites due to carcinomatous peritonealitis of refractory gastric cancer to that of ChT only and/or cellular immunotherapy after failing ChT. A total of 22 pts, 8 underwent only conventional ChT (Group A), 6 performed cellular IT after failing ChT (Group B) and 8 underwent combination therapy (Group C), were enrolled in this retrospective study. ChT was based on conventional conditioning regimen with a standard dose for gastric cancer cases: S-1 (80-120 mg/body) plus paclitaxel (60-80 mg/m2), or CPT-11 (70-80 mg/m2) plus CDDP (80 mg/m2). Autologous tumor cells stimulated with T lymphocytes (AuTL), a kind of CTL, were generated ex vivo from peripheral blood lymphocytes over a two-week co-culturing process with autologous tumor cells separating from the ascites. IT was performed for pts of Group B and C. AuTLs were administered twice prior to ChT for pts of Group C, and were injected 1 x /2 weeks directly into the peritoneal cavity. The treatment was repeated at least three cycles with one-week interval. The mean survival period of Group A, B and C was 8.4, 5.2 and 11.3 months, respectively, and 1 pt in Group A and 3 pts in Group C survived over one year. Adverse events related to both of the ChT and AuTL transfer at all doses were minimal. Ascites had decreased or disappeared in 8 pts in this study. Lymphocytes of ascites were evaluated for cytokine production and subset of CD4+CD25+ T cell before the treatment, and after 3 treatments. The group C pts had increased IFN-gamma and IL-12 production with no TGF-beta1 responses by their ascites after 3 treatments. In contrast, the group A and B had no IFN-gamma, IL-12 or TGF-beta1 responses. These data show that combination therapy of CTL transfer and ChT is a feasible option for patients with refractory peritoneal carcinomatous of gastric cancer without serious adverse events. Although it depends on each mechanism of IT and ChT, a more stringent evaluation of CTL transfer combined with ChT for refractory gastric cancer should be performed.

17Beta-estradiol induces down-regulation of Cap43/NDRG1/Drg-1, a putative differentiation-related and metastasis suppressor gene, in human breast cancer cells.

PURPOSE: Cap43 is known as a nickel- and calcium-inducible gene. In the present study, we examined whether 17beta-estradiol (E2) could affect the expression of Cap43 in breast cancer. EXPERIMENTAL DESIGN: Real-time PCR, immunoblotting, and immunocytochemistry were used to examine the expression of Cap43 and estrogen receptor-alpha (ER-alpha) in breast cancer cell lines. MDA-MB-231 and SK-BR-3 cell lines were transfected with ER-alpha cDNA to establish cells overexpressing ER-alpha. Immunohistochemistry was used to evaluate the expression of the Cap43 protein in breast cancer patients (n = 96), and the relationship between Cap43 expression and clinicopathologic findings was examined. RESULTS: Of the eight cell lines, four expressed higher levels of Cap43 with very low levels of ER-alpha, whereas the other four expressed lower levels of Cap43 with high ER-alpha levels. Treatment with E2 decreased the expression of Cap43 dose-dependently in ER-alpha-positive cell lines but not in ER-alpha-negative lines. Administration of antiestrogens, tamoxifen and ICI 182780, abrogated the E2-induced down-regulation of Cap43. Overexpression of ER-alpha in both ER-alpha-negative cell lines, SK-BR-3 and MDA-MB-231, resulted in down-regulation of Cap43. Immunostaining studies showed a significant correlation between Cap43 expression and the histologic grade of tumors (P = 0.0387). Furthermore, Cap43 expression was inversely correlated with the expression of ER-alpha (P = 0.0374). CONCLUSIONS: E2-induced down-regulation of Cap43 seems to be mediated through ER-alpha-dependent pathways in breast cancer cells both in culture and in patients. Cap43 has potential as a molecular marker to determine the therapeutic efficacy of antiestrogenic anticancer agents in breast cancer.