Overexpression of the drug resistance-associated protein metallothionein does not correlate with response of sarcomas to isolated limb perfusion treatment

Hyperthermic isolated limb perfusion with TNF-α and melphalan (HILP-TM) achieves high response rates in sarcomas. Melphalan resistance was previously reported to be associated with overexpression of metallothioneins (MTs). Objective of this study was to investigate the influence of MT expression on tumor responses in HILP-TM-treated soft tissue (STSs) and bone sarcomas (BS). In primary biopsies of 41 HILP-TM-treated sarcomas (37 STSs and 4 BS), MT expression was assessed by an immunoreactive score. The pathologic response to HILP-TM was quantified in the corresponding tumor resection specimens. We studied the association of MT-IRS between histological regression (responder >90%, or non-responder ≤90% regression), tumor proliferation, and other clinico-pathological parameters. MT expression was found in 70.7% (N = 29) of tumors (high 12.2%, moderate 19.5%, and low 39.0%). After HILP-TM, 20 cases (48.8%) were categorized as “responders” and 21 (51.2%) as “non-responders.” Six “responders” (14.6%) presented with complete regression. MT expression positively correlated with tumor proliferation but not with HILP-TM. HILP-TM showed a favorable response in a high rate of sarcomas. Although MT overexpression was observed in this cohort of sarcomas, the immunohistochemical MT status was not predictive of the tumor response after HILP-TM treatment

Different micro-RNA expression profiles distinguish subtypes of neuroendocrine tumors of the lung: results of a profiling study

MicroRNAs (miRNAs) are a class of small (similar to 22 nucleotides), non-coding, highly conserved single-stranded RNAs with posttranscriptional regulatory features, including the regulation of cell proliferation, differentiation, survival, and apoptosis. They are deregulated in a broad variety of tumors showing characteristic expression patterns and can, thus, be used as a diagnostic tool. In contrast to non-small cell carcinoma of the lung neuroendocrine lung tumors, encompassing typical and atypical carcinoids, small cell lung cancer and large cell neuroendocrine lung cancer, no data about deregulation of tumor entity-specific miRNAs are available to date. miRNA expression differences might give useful information about the biological characteristics of these tumors, as well as serve as helpful markers.In 12 pulmonary neuroendocrine tumors classified as either typical carcinoid, atypical, large cell neuroendocrine or small cell lung cancer, screening for 763 miRNAs known to be involved in pulmonary cancerogenesis was conducted by performing 384-well TaqMan low-density array real-time qPCR. In the entire cohort, 44 miRNAs were identified, which showed a significantly different miRNA expression. For 12 miRNAs, the difference was highly significant (P < 0.01). Eight miRNAs showed a negative (miR-22, miR-29a, miR-29b, miR-29c, miR-367*; miR-504, miR-513C, miR-1200) and four miRNAs a positive (miR-18a, miR-15b*, miR-335*, miR-1201) correlation to the grade of tumor biology. The miRNAs let-7d; miR-19; miR-576-5p; miR-340*; miR-1286 are significantly associated with survival. Members of the miR-29 family seem to be extremely important in this group of tumors. We found a number of miRNAs, which showed a highly significant deregulation in pulmonary neuroendocrine tumors. Moreover, some of these deregulated miRNAs seem to allow discrimination of the various subtypes of pulmonary neuroendocrine tumors. Thus, the analysis of specific sets of miRNAs can be proposed as diagnostic and/or predictive markers in this group of neoplasias