[Importance of next generation sequencing in precision oncology approach of acute myeloid leukemia]

In contrast to solid tumours, the genetic background of acute myeloid leukemia (AML) is characterized by a relatively low number of alterations per sample (average 3-5 mutations similarly to paediatric malignancies). Although the mutational background is rather heterogeneous, the detection of genetic alterations has diagnostic, prognostic and therapeutic relevance. We investigated cytogenetic and most commonly occurring molecular genetic alterations, and their co-occurrence in 830 AML patients diagnosed and treated in our institute between 2001 and 2019. Results from the recently introduced next generation sequencing for seven AML patients are also presented. Both methods (previously performed standard PCR-based tests and NGS) achieved the same results for commonly occurring mutations, but NGS technique was capable to identify further, rarely occurring mutations which bear diagnostic and prognostic importance according to the recent European LeukemiaNet recommendations. The introduction of NGS techniques to routine laboratory diagnostic applications is a required step following international expertise.

Current Trends in Applications of Circulatory Microchimerism Detection in Transplantation

Primarily due to recent advances of detection techniques, microchimerism (the proportion of minor variant population is below 1%) has recently gained increasing attention in the field of transplantation. Availability of polymorphic markers, such as deletion insertion or single nucleotide polymorphisms along with a vast array of high sensitivity detection techniques, allow the accurate detection of small quantities of donor- or recipient-related materials. This diagnostic information can improve monitoring of allograft injuries in solid organ transplantations (SOT) as well as facilitate early detection of relapse in allogeneic hematopoietic stem cell transplantation (allo-HSCT). In the present review, genetic marker and detection platform options applicable for microchimerism detection are discussed. Furthermore, current results of relevant clinical studies in the context of microchimerism and SOT or allo-HSCT respectively are also summarized.

Proteasome Subunit Beta Type 1 P11A Polymorphism Is a New Prognostic Marker in Multiple Myeloma

BACKGROUND

Proteasome subunit beta type 1 (PSMB1) rs12717 polymorphism, a single nucleotide polymorphism with unknown functional effect, was recently reported to influence response to bortezomib-based therapy in follicular lymphoma.

PATIENTS AND METHODS

We retrospectively analyzed the prognostic impact of this polymorphism in 211 consecutively diagnosed multiple myeloma cases, and performed in vitro experiments to look into its functional consequences.

RESULTS

On univariate analysis, patients carrying the variant G allele showed significantly shorter progression-free survival (PFS) with a pattern suggestive of a gene-dose effect (PFS 26.4, 22.3, and 16.4 months in C/C, C/G, and G/G patients, respectively, P = .002). On multivariate analysis, carrying the G/G genotype was a significant independent risk factor for relapse (hazard ratio [HR] 2.29, P < .001) with a similar trend in C/G carriers (HR 1.33, P = .097) when compared with the major allele carrier C/C cohort. Our subsequent in vitro analyses demonstrated significantly reduced protease activity in proteasomes of individuals with G/G genotype compared with that of C/C carriers, despite that PSMB1 expression and proteasome assembly remained unaltered. Bortezomib exhibited a lower inhibitory capacity on the caspase- and trypsin-like activity of proteasomes from G/G individuals.

CONCLUSION

Our results show that carriership of PSMB1 rs12717 minor allele is predictive for suboptimal response with bortezomib treatment, which could be explained by less active proteasomes that are less sensitive to bortezomib, and myeloma cells consequently relying on other escape mechanisms to cope with the abundance of misfolded proteins.