Can survivin expression predict the response to bortezomib in cases with mantle cell lymphoma?

Molecular outcome prediction in mantle cell lymphoma

Mantle cell lymphoma (MCL), a subtype of B-cell non-Hodgkin lymphoma, is usually incurable with current therapeutic approaches and the clinical course displays considerable variability. Objective assessment of the efficacy of new and more tailored treatment strategies requires deeper molecular insights into the disease and more individual risk assessment. The molecular feature of tumor cell proliferation as measured by Ki-67 immunohistochemistry or, more precisely, by microarray-based gene-expression profiling, has been shown to be of strong predictive value in MCL. The recently proposed quantitative reverse transcription-PCR based five-gene model survival predictor is applicable to fresh-frozen and routinely obtained formalin-fixed and paraffin-embedded tumor tissues, and provides the potential to investigate its prognostic value in prospective clinical trials of MCL patients.

Preclinical studies of the proteasome inhibitor bortezomib in malignant pleural mesothelioma

Malignant pleural mesothelioma (MPM) is a highly lethal neoplasm that is resistant to chemotherapy. Bortezomib is an FDA-approved proteasome inhibitor that is currently under clinical investigation in multiple neoplasms but has not been studied extensively in MPM. In this report, we determine the biological and molecular response of cultured MPM cells to bortezomib alone and in combination with cisplatin or pemetrexed. We used four MPM cell lines (MS589, H28, H2052, JMN), a normal mesothelial cell line (HM3), and a lung cancer cell line (H23) in survival studies utilizing bortezomib, cisplatin, and pemetrexed alone and in combination by administering concurrently or by varying the order of administration. We determined the effect of bortezomib on the cell cycle, apoptosis, and on the expression of cell cycle proteins p21/WAF1 and p27/KIP1 and on apoptosis-related proteins IAP-1, IAP-2, survivin, and XIAP. Bortezomib was highly cytotoxic to MPM cells and induced both G(2)/M and G(1)/S cell cycle arrest. Apoptosis increased in a concentration- and time-dependent manner in 3 of 4 MPM cell lines. Bortezomib stabilized or increased protein levels of p21/WAF1 and IAP-1 and to a lesser degree p27/KIP1, IAP-2, XIAP, and survivin. In combination studies with cisplatin, bortezomib was generally synergistic at high concentrations and antagonistic at low concentrations. Bortezomib increased the cytotoxicity of cisplatin and pemetrexed in a concentration-dependent manner when administered prior to either. Bortezomib may improve outcome in MPM patients alone or in combination with standard chemotherapy but the order of administration is likely to be important. This study justifies further evaluation of bortezomib in MPM.