Gene amplification in esophageal adenocarcinomas and Barrett's with high-grade dysplasia.

PURPOSE: The purpose of this study was to determine the frequency and overall contribution of specific gene amplification events in the formation of Barrett's adenocarcinomas. The relationship of gene amplification to clinical-pathological variables and its potential usefulness as a marker for early cancer detection were also examined. EXPERIMENTAL DESIGN: We used quantitative PCR and Southern blot analysis to screen 87 cases of Barrett's adenocarcinoma for the presence or absence of 13 distinct gene amplification events. Gene amplification was then examined for correlation with other amplification events and clinical variables (survival, stage, nodal involvement, tumor invasion, smoking history, and gender). Additionally, 22 specimens of Barrett's with high-grade dysplasia (HGD) were examined for the presence of gene amplification. RESULTS: One or more amplification events were present in 50 of 87 (57%) adenocarcinomas. The ERBB2 gene was amplified in 19 of 87 (21.8%), CCNE1 in 11 of 87 (12.6%), GATA4 in 9 of 87 (10.3%), KRAS in 9 of 87 (10.3%), EGFR in 7 of 87 (8.0%), CCND1 in 6 of 87 (6.8%), HNF3alpha in 5 of 87 (5.7%), PIK3CA in 5 of 87 (5.7%), C-MYC in 4 of 87 (4.6%), DYRK2 in 2 of 87 (2.3%), and AIB1, AKT1, and IGF1R were amplified in 0 of 87 (0%) of the tumors. CCND1 amplification was found to correlate negatively with survival (P < 0.05). In addition, the ERBB2 amplicon positively correlated (P < 0.05) with GATA4 amplification. Increased copy number of the ERBB2 (1 of 22), GATA4 (1 of 22), KRAS (2 of 22), C-MYC (1 of 22), CCNE1 (2 of 22), and CCND1 (2 of 22) genes was also observed in one or more Barrett's adenocarcinomas with HGD. CONCLUSIONS: The high frequency of gene amplification in esophageal adenocarcinomas and HGD indicates the important role of these events in esophageal adenocarcinoma development. Additionally, these results underscore the possible usefulness of early detection approaches and chemotherapeutic strategies (ErbB2 and cyclin D1) targeted against amplified gene products.     

Hormone-refractory breast cancer remains sensitive to the antitumor activity of heat shock protein 90 inhibitors.

PURPOSE: The antiestrogen tamoxifen (Tam) has been used as therapy against estrogen receptor (ER)-positive breast cancer for decades. Most tumors respond initially, but resistance frequently develops. The ER exists in a multiprotein complex containing the molecular chaperone heat shock protein (Hsp) 90, which is known to regulate the stability and activity of this receptor. Therefore, we investigated a ligand-independent approach to hormonal therapy that depletes cellular levels of the receptor by inhibiting the function of Hsp90. EXPERIMENTAL DESIGN: The activity of the Hsp90 inhibitor geldanamycin (GA) and its clinically relevant derivative, 17-allylamino-17-demethoxygeldanamycin (17AAG), was examined at the molecular and cellular levels using Tam-resistant MCF-7 breast cancer cells both in vitro and in tumor xenografts. RESULTS: The ER was depleted by GA in several Tam-resistant cell lines, as were other Hsp90 client proteins such as Akt and Raf-1. Unexpectedly, Tam inhibited ER depletion by GA but had no effect on destabilization of Akt or Raf-1. When SCID mice supplemented with Tam were treated with 17AAG, their tumors also showed no decrease in ER levels as measured by immunofluorescent staining and laser scanning cytometry. In these same tumors, however, decreased Akt and Raf-1 levels were observed. Drug administration also led to inhibition of tumor xenograft growth. The mechanism by which Tam inhibits GA-mediated ER depletion is unclear, but immunoprecipitation experiments showed that Tam does not inhibit the ability of GA to alter the ER-chaperone complex. CONCLUSIONS: Based on its ability to deplete the ER as well as other critical signaling molecules in Tam-resistant breast cancer, 17AAG may provide a useful alternative treatment for patients with recurrent, hormone-refractory breast cancer that should be explored further in Phase II trials. In this context, combined treatment with 17AAG and Tam should be avoided because Tam may inhibit the ability of 17AAG to deplete the ER, potentially reducing its anticancer activity.     

Centrosome aberrations as a possible mechanism for chromosomal instability in non-Hodgkin's lymphoma.

Recently, centrosome aberrations have been described as a possible cause of aneuploidy in many solid tumors. To investigate whether centrosome aberrations occur in non-Hodgkin's lymphoma (NHL) and correlate with histologic subtype, karyotype, and other biological disease features, we examined 24 follicular lymphomas (FL), 18 diffuse large-B-cell lymphomas (DLCL), 33 mantle cell lymphomas (MCL), and 17 extranodal marginal zone B-cell lymphomas (MZBCL), using antibodies to centrosomal proteins. All 92 NHL displayed numerical and structural centrosome aberrations as compared to nonmalignant lymphoid tissue. Centrosome abnormalities were detectable in 32.3% of the cells in NHL, but in only 5.5% of lymphoid cells from 30 control individuals (P<0.0001). Indolent FL and MZBCL contained only 25.8 and 28.8% cells with abnormal centrosomes. In contrast, aggressive DLCL and MCL harbored centrosome aberrations in 41.8 and 35.0% of the cells, respectively (P<0.0001). Centrosomal aberrations correlated to lymphoma grade, mitotic, and proliferation indices, but not to the p53 labeling index. Importantly, diploid MCL contained 31.2% cells with abnormal centrosomes, while tetraploid samples harbored centrosome aberrations in 55.6% of the cells (P<0.0001). These results indicate that centrosome defects are common in NHL and suggest that they may contribute to the acquisition of chromosomal instability typically seen in NHL.     

Technetium-99m tetrofosmin SPECT predicts chemotherapy response in small cell lung cancer.

The multidrug resistance gene 1 encoding human P-glycoprotein (Pgp) is thought to play an important role in the multidrug resistance of lung cancer. The purpose of this study was to predict chemotherapy response by technetium-99m tetrofosmin (Tc-99m TF) lung single photon emission computed tomography (SPECT) and compare Pgp expression in patients with untreated small cell lung cancer (SCLC). Forty patients with untreated SCLC received Tc-99m TF lung SPECT prior to chemotherapy. The chemotherapy response was evaluated in the 3rd month after completion of treatment. Immunohistochemical staining of Pgp expression was performed on multiple nonconsecutive sections of biopsy specimens. By quantitative analyses, tumor to background ratios were 1.86 +/- 0.27 and 1.17 +/- 0.26 for patients with a good and poor response, respectively (p < 0.05). All of the 20 patients with a good chemotherapy response also had a positive Tc-99m TF lung SPECT and negative Pgp expression. In contrast, only 4 of the 20 patients with a poor chemotherapy response had a positive Tc-99m TF lung SPECT. Moreover, 10 of the 20 patients with a poor chemotherapy response also had negative Pgp expression (p < 0.05). Therefore, we concluded that Tc-99m TF lung SPECT can accurately predict the chemotherapy response, and Tc-99m TF lung SPECT findings can be partially compatible with Pgp expression in patients with untreated SCLC.     

Tissue factor expression correlates with tumor angiogenesis and invasiveness in human hepatocellular carcinoma.

PURPOSE: Recent studies have shown that tissue factor (TF) may be involved in tumor angiogenesis and metastasis. The role of TF in hepatocellular carcinoma (HCC) was unknown. This study evaluated whether TF expression correlates with microvessel density (MVD), vascular endothelial growth factor (VEGF) expression, tumor invasiveness, and prognosis in human HCC. EXPERIMENTAL DESIGN: Tissue samples were obtained from 58 specimens of resected HCC. Immunohistochemical expression of TF was examined, and tumor MVD was evaluated using CD34 as the endothelial marker. TF and VEGF protein levels in the tumor cytosol were quantified by ELISA. Clinicopathologic and follow-up data of patients were prospectively collected. RESULTS: The immunohistochemical expression of TF in the tumors correlated significantly with tumor MVD (P = 0.002). The median cytosolic TF protein level in the tumors was 720 pg/mg total protein (range, 67-2406 pg/mg total protein). A significant positive correlation was found between TF and VEGF levels in the tumor cytosol (r = 0.475, P < 0.001). High tumor cytosolic TF level was associated with venous invasion (P = 0.004), microsatellite nodules (P = 0.024), unencapsulated tumor (P = 0.007), and advanced tumor stage (P = 0.010). A higher than median tumor cytosolic TF level was an independent predictor of poor survival (risk ratio, 1.836; 95% confidence interval 1.130-5.312, P = 0.023). CONCLUSIONS: This study shows that TF is related to tumor angiogenesis and invasiveness in HCC. Evaluation of tumor TF expression may be useful as a prognostic indicator in patients with HCC.     

Effect of adult microsurgical varicocelectomy on testicular volume

OBJECTIVES: To re-examine the potential influence of varicocelectomy on testicular volume using scrotal ultrasonography, because it has been reported that total testicular volume (assessed by physical examination) increases after adult varicocele ligation. METHODS: A retrospective review of the testicular volume and semen parameters of 61 men who underwent microsurgical varicocelectomy between 1996 and 1998 was performed. Ultrasound-derived testicular volumes and total motile sperm counts were compared before varicocelectomy and at a mean of 7.2 months postoperatively. RESULTS: Bilateral varicocelectomy was performed in 22 men; 39 men underwent a left-sided procedure only. Overall, no significant change was found in the mean total testicular volume after varicocelectomy compared with preoperatively (24.0 versus 23.9 mL, respectively; P = 0.74). Similarly, the testicular volumes did not change significantly after left or bilateral varicocelectomy (P >0.05). Overall, the mean total motile sperm count increased significantly after varicocelectomy (17. 9 to 25.4, P = 0.05). CONCLUSIONS: This was the first study to examine the effect of adult varicocelectomy on testicular volume using ultrasound-derived measurements of volume. Unlike previous findings, our data suggest that although adult varicocelectomy improves semen quality in most infertile men, it does not result in a significant increase in testicular volume.