Faculty Bibliography

Malignant mesothelioma (MM) is a cancer of the lining of the lungs, heart, and intestine and is known to respond poorly to chemotherapy. Here we show that malignant mesothelial cells have an elevated Notch signaling pathway compared with normal human mesothelial cells. We studied the role of Notch in MM under normoxic and hypoxic conditions, the latter condition best recapitulating the MM microenvironment. Genetic and chemical modulation of the Notch pathway indicated that MM cells are dependent on Notch signaling. More specifically, this signaling was Notch-1 dependent as the result of its negative transcriptional regulation on phosphatase and tensin homologue (PTEN), which led to activation of the prosurvival phosphatidylinositol 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) signaling pathway. Our study also provides evidence that whereas Notch-1 is elevated in the malignant setting, Notch-2 is diminished. This differential expression of the two Notch isoforms benefits cancer cell survival because reexpression of Notch-2 was toxic to MM cells. The mechanism of Notch-2 toxicity to MM cells countered that of Notch-1, as it was the result of positive transcriptional regulation of PTEN and inhibition of the PI3K/Akt/mTOR signaling pathway. These results provide new insight into the role of Notch in MM and suggest that Notch pathway inhibitors may be useful in the treatment of this deadly disease

Bone morphogenetic proteins (BMPs) belong to the transforming growth factor-beta superfamily. Recent studies have showed that aberrant methylation of BMP genes is present in several types of human cancer. We examined the expression and methylation status of BMP3b and BMP6 in malignant pleural mesotheliomas (MPMs). The expression status of BMP3b, and BMP6 mRNAs were examined in seven MPM cell lines by RT-PCR assay. The expression of BMP3b was completely suppressed in 2 and partially suppressed in 2 of 7 cell lines and expression of BMP6 was partially suppressed in 2 cell lines. Methylation status of BMP3b in cell lines was determined by methylation-specific assay to find aberrant methylation in 6 cell lines which include 4 cell lines with suppressed BMP3b expression. Partial methylation of BMP6 was found in 2 cell lines whose expression was partially suppressed. Treatment with 5-Aza-dC restored BMP3b expression in methylated cell lines. Next, we examined the methylation status in 57 surgically resected MPM cases and found aberrant methylation of BMP3b in 9 (53%) out of 17 cases from Japan and 3 (8%) of 40 cases from USA and that of BMP6 in 4 (24%) cases from Japan and 12 (30%) cases from USA, showing significant difference in frequency of BMP3b methylation between MPMs of the two countries (P=0.0004). Our study indicated that BMP3b and BMP6 genes were suppressed by DNA methylation and methylation of BMP3b is significantly frequent in Japanese MPMs, suggesting its pathogenic role and the ethnic difference in MPMs

OBJECTIVE: In the 2003 Supplement for tumor, node, metastasis (TNM) Staging classification it states that TNM staging 'applies to all types of carcinoma including small cell carcinoma; however, it does not apply to carcinoids.' Despite this caveat, most publications on typical and atypical carcinoids use the TNM staging system for nonsmall cell carcinoma and are able to demonstrate prognostic significance for the different stages. For this reason, as the next TNM Staging proposal is being considered, we sought to investigate the carcinoid cases submitted to the International Association for the Study of Lung Cancer (IASLC) database, as well as the National Cancer Institute Surveillance Epidemiology and End Results (SEER). MATERIALS AND METHODS: In the data collected for the IASLC Staging Project database over the time period 1990 to 2000, there were 513 broncho-pulmonary carcinoids. A total of 1619 broncho-pulmonary carcinoid cases diagnosed over the period 1990-2002 were analyzed from the SEER database, including 1437 surgical cases. Pathologic slides were not available for histologic review. RESULTS: Most of tumors in both the IASLC and SEER databases were Stage I (82% and 78%, respectively), as defined by the IASLC proposals for the 7th edition of TNM staging system. T status was a statistically significant predictor of survival for both the SEER data (p < 0.0001) and the IASLC database (p = 0.0156), though for different reasons. N status showed significant survival correlations in both data sets (p < 0.0001). The effect of M status was significant (p < 0.0001) within the SEER data and not studied in the IASLC cases, which were almost exclusively M0. We found that all three T, N, and M categories as defined for non-small cell lung cancer are generally useful for staging of pulmonary carcinoid tumors. Significant differences in survival for overall stages I versus II versus III/IV were identified in both data sets. Patients with multiple same lobe nodules had a 100% 5-year survival, which may be a reason to reevaluate their status in the IIB category in future analyses. CONCLUSIONS: In summary, the IASLC proposals for the 7th edition of TNM are helpful in predicting prognosis for broncho-pulmonary carcinoid tumors. It is the recommendation of the IASLC Staging project that TNM be applied to broncho-pulmonary carcinoid tumors. A prospective collection of data through an International Registry of Pulmonary Neuroendocrine Tumors planned by the IASLC will allow for further detailed analysis of staging data for broncho-pulmonary carcinoids

BACKGROUND: Advances in translational research have led to the need for well characterized biospecimens for research. The National Mesothelioma Virtual Bank is an initiative which collects annotated datasets relevant to human mesothelioma to develop an enterprising biospecimen resource to fulfill researchers' need. METHODS: The National Mesothelioma Virtual Bank architecture is based on three major components: (a) common data elements (based on College of American Pathologists protocol and National North American Association of Central Cancer Registries standards), (b) clinical and epidemiologic data annotation, and (c) data query tools. These tools work interoperably to standardize the entire process of annotation. The National Mesothelioma Virtual Bank tool is based upon the caTISSUE Clinical Annotation Engine, developed by the University of Pittsburgh in cooperation with the Cancer Biomedical Informatics Grid (caBIG, see http://cabig.nci.nih.gov). This application provides a web-based system for annotating, importing and searching mesothelioma cases. The underlying information model is constructed utilizing Unified Modeling Language class diagrams, hierarchical relationships and Enterprise Architect software. RESULT: The database provides researchers real-time access to richly annotated specimens and integral information related to mesothelioma. The data disclosed is tightly regulated depending upon users' authorization and depending on the participating institute that is amenable to the local Institutional Review Board and regulation committee reviews. CONCLUSION: The National Mesothelioma Virtual Bank currently has over 600 annotated cases available for researchers that include paraffin embedded tissues, tissue microarrays, serum and genomic DNA. The National Mesothelioma Virtual Bank is a virtual biospecimen registry with robust translational biomedical informatics support to facilitate basic science, clinical, and translational research. Furthermore, it protects patient privacy by disclosing only de-identified datasets to assure that biospecimens can be made accessible to researchers

BACKGROUND: Tetrathiomolybdate (TM) is an oral copper-depleting agent that has been shown to inhibit angiogenesis, and angiogenesis is a predictor of poor prognosis in malignant pleural mesothelioma. We hypothesized that cytoreduction of malignant pleural mesothelioma followed by TM will delay time to progression. METHODS: Between November 2000 and August 2003, 30 patients with malignant pleural mesothelioma received postoperative TM beginning 4 to 6 weeks after surgery at a dose adjusted to keep ceruloplasmin between 5 and 15 mg/dL). Time to progression was compared with the 55 stage I and II patients and 109 stage III patients previously treated with cytoreduction by one of us (H.P.). RESULTS: The 30 patients (25 men, 5 women; 13 stage I and II, 17 stage III), median age 67 years (range, 49-81 years), remained on TM a median of 14.9 months (range, 2 to 57 months). All patients reached target ceruloplasmin levels at a mean of 34 +/- 2 days (95% confidence interval, 30 to 39 days), and vascular endothelial growth factor levels at baseline (ceruloplasmin = 45.2 +/- 2 mg/dL) decreased from 2,086 +/- 390 pg/mL to 1,250 +/- 712 pg/mL (p < 0.002) at target ceruloplasmin (13 +/- 2 mg/dL; p < 0.0001 from baseline). The time to progression for all stage I or II TM patients was 20 months whereas that of 55 stage I or II non-TM-treated patients was 10 months (p = 0.046 versus TM). No differences in time to progression for the stage III TM patents from surgery were seen (7 months). CONCLUSIONS: Tetrathiomolybdate has antiangiogenic effects in malignant pleural mesothelioma patients after resection of gross disease, and exhibits minimal toxicity and comparable efficacy to previous multimodality trials. Tetrathiomolybdate should be evaluated for efficacy in combination with standard malignant pleural mesothelioma regimens, as well as for postsurgical maintenance therapy