Gene expression profiling in diffuse large B-cell lymphoma

Fc-gamma-receptor IIIa polymorphism and gene expression profile do not predict the prognosis in diffuse large B-cell lymphoma treated with R-CHOP protocol

The addition of rituximab to conventional chemotherapy has significantly improved the treatment outcome in diffuse large B-cell lymphoma. However, differences in treatment response and survival data can be observed independently from the International Prognostic Index scores. The current study evaluated the impact of Fc-gamma-receptor IIIa polymorphism and gene expression profile on the response of DLBCL patients to R-CHOP therapy as well as on their survival results. Fifty-one patients were involved, thirty-two females, nineteen males, their median age was 53.1 years. The FCGR3A polymorphism at the 158. amino acid position determined with PCR method showed the following results: VV: 12 cases (23.5%), VF: 29 cases (56.8%) and FF: 10 cases (19.6%), respectively. There was no significant difference between the treatment responses of the three groups. The event-free survival data were less favorable in the F-allele carriers than in V/V homozygous patients, but without any significancy, and the overall survival curves were almost the same. As for the gene expression profile, 20 patients' biopsy specimens showed germinal center and 31 showed non-germinal center characteristics. Treatment results did not differ from each other in the two groups. Both the event-free and the overall survival data were more favorable in the GC group, however the differences were not significant. Our results contest the predictive value of Fc-gamma-receptor IIIa polymorphism and gene expression profile in diffuse large B-cell lymphoma.

MicroRNA expression differentiates between primary lung tumors and metastases to the lung

For surgical pathologists, distinguishing whether a pulmonary neoplasm is primary or metastatic can be challenging, and current biomarkers do not always aid lung tumor classification. The tissue-associated expression of microRNA likely explains the remarkable finding that many tumors can be classified based solely on their microRNA expression signature. Here we show that microRNAs can serve as biomarkers for lung tumor classification. Using microRNA microarray data generated from 76 formalin-fixed, paraffin-embedded (FFPE) samples of either primary lung cancer or metastatic tumors to the lung, we have identified a set of microRNAs expressed differentially between these two groups. This set includes hsa-miR-182, which was most strongly over-expressed in the lung primary tumors, and hsa-miR-126, which was over-expressed in the metastatic tumors. The differential expression of this set of microRNAs was confirmed using qRT-PCR on a set of 54 samples. In light of our data, microRNA expression should be considered as a potential clinical biomarker for surgical pathologists faced with discerning the tumor type of an inscrutable lung neoplasm.