MATERIALS OF NOBEL SYMPOSIUM 175: PRECISION MEDICINE TRANSFORMS HEALTHCARE: A NEW TRAJECTORY FOR RESEARCH AND INNOVATION SEPTEMBER 20-22, 2023, STOCKHOLM, SWEDEN

Nobel Symposium 175 was organized by Professor Richard Rosenquist Brandell of Karolinska Institutet and was supported by the Royal Swedish Academy of Sciences. The focus of the symposium was a discussion on the development of precision medicine in infectious and rare diseases, cancer, and complex diseases. Presentations and discussions concerned new technologies, bioinformatics, and new diagnostic and therapeutic approaches based on findings in basic research. Organization of precision medicine models and their implementation in medical practice at the national and international levels were also on the agenda. 29 scientists from different fields of medicine presented their work during a three-day exciting trip into the future of patient' care. Panel discussions shed light on the development of precision medicine for better treatment of patients.

Comparative Analysis of the Embryonal Brain Tumors Based on Their Molecular Features

Pediatric brain tumors currently show the highest incidence among solid childhood malignancies and, together with leukemia, are the leading cause of death from cancer in childhood. Embryonal brain tumors are the most common and frequent type of childhood brain cancer and are usually characterized by an extremely aggressive course of the disease with the worst outcomes in most cases. There is an urgent need for specific refined molecular diagnostics, which would help to develop personalized treatment. In the present review paper, the latest molecular characteristics of various classified forms of embryonal brain tumors were analyzed in detail. Overexpression of the MYC and MYCN genes is characteristic of many embryonal brain tumors, leading to enhanced cell proliferation and disturbances in the cell cycle. The functioning of the SWI2/SNF2 chromatin remodeling complex are distorted in such malignancies as well. Noteworthy, LIN28 and MYC discussed here are involved in the induction of pluripotency. We have to mention that molecular mechanisms underlying the development of embryonal brain tumors of the central nervous system (CNS) are still not well understood. Thus, it is important to uncover such mechanisms with the aim to provide a better prognosis of the course of disease and to create personalized therapy.

STK4 protein expression pattern follows different trends in endometrioid and serous endometrial adenocarcinoma upon tumor progression

In a previous study, we showed that serine/threonine-protein kinase 4 (STK4) is involved in the control on proliferation and migration of endometrial cancer (EC) cells in vitro. In the present paper, we studied STK4 expression in EC tissues from a large cohort of patients to determine whether STK4 can serve as a marker for the aggressiveness and prognosis of EC. Tissue samples from patients with EC were examined for tumor type, grade, and stage. The STK4 protein expression in EC cells was assessed by immunohistochemistry and related to clinicopathological data of patients, such as progression and patient survival rate. The STK4 mRNA levels and its relation to the survival rate were analyzed also in publicly available databases. The STK4 gene expression was low at both, the mRNA and protein levels in EC, especially in serous tumors. Comparison of STK4 expression with the patient survival rate shows that the higher expression is associated with worse prognosis in serous EC, while no such dependence was found in endometrioid EC. Hence, the determination of the SKT4 expression pattern could be used as a putative prognostic marker for serous EC.

DIFFERENTIAL EXPRESSION PATTERN OF AIP, UCKL1, AND PKN1 GENES IN PROSTATE CANCER PATIENTS

BACKGROUND

The evolution of research on the therapy of prostate cancer (PC) depends on a study of molecules that are involved in the progression of this disease. Nevertheless, there is a need for additional biomarkers that would help to refine the molecular profile of PC and propose the personalized therapeutic approach.

AIM

To study differential expression patterns of the AIP, UCKL1, and PKN1 genes in blood sera and tumor tissue of patients with PC with different Gleason scores.

MATERIALS AND METHODS

The total extracellular RNA was isolated from blood sera of 44 PC patients and 4 healthy donors. cDNAs were synthesized and quantitative polymerase chain reaction (qPCR) was performed. Immunohistochemical study of the UCKL, AIP and PKN1 proteins was performed on deparaffinized sections of tumors. The study was supplemented by a bioinformatic analysis of the publicly available databases.

RESULTS

The UCKL1, AIP, PKN1 genes were overexpressed at the mRNA level in blood sera of PC patients, compared to healthy donors. Extracellular mRNA levels of AIP and UCKL-1 were 100-1000-fold increased in all PC samples compared to the healthy donors but without significant inequality between the groups of PC cases differing by the Gleason score. The highest levels were detected in the samples from PC patients with the Gleason score > 9. The PKN1 expression was higher in PC patients compared with healthy donors but without significant difference between the groups.

CONCLUSIONS

From the three chosen genes, AIP and UCKL1 showed similar pattern of expression assessed either by extracellular mRNA levels in patient sera or the protein in PC tissues. AIP was up to 1000-fold increased in all PC samples, compared to the healthy donors, with the highest levels in PC cases with Gleason score > 9. Expression levels of the AIP and UCKL1 genes in the PC patient sera may be used as an additional criterion for prognosis of tumor progression.

Upregulation of PKN1 as a Prognosis Biomarker for Endometrial Cancer

BACKGROUND

Several markers of survival among endometrial cancer (EC) patients have been proposed, namely, the oncoprotein stathmin, RAF kinase inhibitor (RKIP), Cyclin A, GATA-binding protein 3 (GATA3), and growth and differentiation factor-15 (GDF-15). Their elevated expression correlated significantly with a high stage, serous papillary/clear cell subtypes, and aneuploidy. In a previous study, we reported the elevated expression of the serine/threonine protein kinase N1 (PKN1) in cancerous cells. In the present paper, we studied PKN1 expression in EC tissues from a large cohort of patients, to determine whether PKN1 can serve as a marker for the aggressiveness and prognosis of EC, and/or as a marker of survival among EC patients.

METHODS

Tissue samples from EC patients were examined retrospectively for tumor type, tumor size, FIGO stage and grade, depth of invasion in the myometrium, and presence of lymph node metastasis. The PKN1 protein expression in EC cells was assessed by immunohistochemistry. PKN1 mRNA levels were analyzed in publicly available databases, using bioinformatic tools.

RESULTS

We found that expression of PKN1 at the mRNA and proteins levels tended to increase in high-grade EC samples (P = .0001 and P = .06, respectively). In addition, patients with metastatic disease had higher PKN1 mRNA levels (P = .02). Moreover, patients with high PKN1 expression could be characterized by poorer survival.

CONCLUSIONS

We have shown a trend of the higher PKN1 expression levels in EC patients with poor prognosis. Therefore, PKN1 might be considered as a candidate prognostic marker for EC.

Differential expression patterns of AIP, UCKL1, and PKN1 genes in breast cancer of different molecular subtypes

BACKGROUND

Classification of breast cancer (BC) in the molecular subtypes had the enormous impact on the development of the individualized therapy. Nevertheless, there is a need for additional biomarkers that would help to refine molecular subtypes of BC and propose the therapeutic approach for each patient.

AIM

To study differential expression patterns of AIP, UCKL1, and PKN1 genes in blood sera and tumor tissue of patients with BC of different molecular subtypes.

MATERIALS AND METHODS

The total extracellular RNA was isolated from serum of 26 BC patients. cDNAs was synthesized and quantitative polymerase chain reaction was performed. Also, immunohistochemical studies of UCKL, AIP and PKN1 were performed on deparaffined tissue sections. The study was supplemented by a bioinformatic analysis of the publicly available databases.

RESULTS

AIP and UCKL-1 extracellular mRNA levels were 100-1000-fold increased in blood sera of all BC patients, compared to the healthy donors. The highest levels were detected in the luminal A and HER2 (ERRB2) BC subtypes. The highest levels of PKN1 were detected blood sera of the patients with luminal B and basal subtypes; its expression levels were just 10-100-fold higher in BC samples compared to healthy donors.

CONCLUSIONS

The UCKL1, AIP, PKN1 genes are overexpressed at the mRNA level in blood sera of BC patients compared to the sera of healthy individuals. Among three genes under study, only for the AIP gene, the pattern of extracellular mRNA expression in sera paralleled to protein expression in BC tissues of each specified molecular subtype.

Expression pattern of MRPS18 family genes in malignantly transformed b-cells

AIM

To compare expression patterns of proteins of a family of mitochondrial ribosomal protein S18 (MRPS18) in tumor cell lines of the B-cell origin.

MATERIALS AND METHODS

The study has been performed on different subsets of tonsil B-cells and tumor cell lines of the B-cell origin using quantitative polymerase chain reaction analysis, western blot analysis, immunohistochemistry, bioinformatic analysis of the publicly available data bases on expression.

RESULTS

We have found that genes of the MRPS18 family (1-3) show different expression patterns in tumor cell lines of the B-cell origin. The highest levels of expression were shown for MRPS18-3, the lowest - for MRPS18-1. MRPS18-2 was expressed at the highest levels in germinal center cells, Burkitt lymphoma and Hodgkin lymphoma cell lines. At the protein levels, MRPS18-2 showed the highest expression in Burkitt lymphoma and B-cell precursor acute lymphoblastic leukemia cell lines. In lymphoblastoid cell lines, and in germinal center B-cells MRPS18-2 levels were somewhat lower, but higher than in memory and plasma B-cells.

CONCLUSIONS

The differential expression pattern of the MRPS18 family proteins suggests that they play various roles in cellular processes.

SLAMF1/CD150 in hematologic malignancies: Silent marker or active player?

SLAMF1/CD150 receptor is a founder of signaling lymphocyte activation molecule (SLAM) family of cell-surface receptors. It is widely expressed on cells within hematopoietic system. In hematologic malignancies CD150 cell surface expression is restricted to cutaneous T-cell lymphomas, few types of B-cell non-Hodgkin's lymphoma, near half of cases of chronic lymphocytic leukemia, Hodgkin's lymphoma, and multiple myeloma. Differential expression among various types of hematological malignancies allows considering CD150 as diagnostical and potential prognostic marker. Moreover, CD150 may be a target for antibody-based or measles virus oncolytic therapy. Due to CD150 signaling properties it is involved in regulation of malignant cell fate decision and tumor microenvironment in Hodgkin's lymphoma and chronic lymphocytic leukemia. This review summarizes evidence for the important role of CD150 in pathogenesis of hematologic malignancies.

The TGF-beta - SMAD pathway is inactivated in cronic lymphocytic leukemia cells

AIM

To study the status of the tumor growth factor beta (TGFB) pathway in chronic lymphocytic leukemia (CLL) cells and to uncover molecular details underlying CLL cell genesis.

OBJECTS AND METHODS

The study was conducted on peripheral blood samples of patients with CLL using the following methods: RNA isolation, analysis of expression of transcription factors using RT2 profiler assay, bioinformatics analysis of publicly available data bases on expression.

RESULTS

We have shown that the TGFB - SMAD canonical pathway is not active in CLL cells. SMAD-responsive genes, such as BCL2L1 (BCL-XL), CCND2 (Cyclin D2), and MYC, are down-regulated in CLL cells compared with peripheral blood B cells of healthy donors.

CONCLUSIONS

The TGFB-mediated signaling is not active in CLL cells due to low (or absent) expression of SMAD1, -4, -5, -9, and ATF-3. Expression and phosphorylation status of SMAD2 and -3 should be further elucidated in the future studies.

CD150 and CD180 are involved in regulation of transcription factors expression in chronic lymphocytic leukemia cells

BACKGROUND

Sequential stages of B-cell development is stringently coordinated by transcription factors (TFs) network that include B-lineage commitment TFs (Ikaros, Runx1/Cbfb, E2A, and FOXO1), B-lineage maintenance TFs (EBF1 and PAX5) and stage specific set of TFs (IRF4, IRF8, BCL6, BLIMP1). Deregulation of TFs expression and activity is often occurs in malignant B cells. The aim of this study was to evaluate TFs expression in chronic lymphocytic leukemia cells taking into consideration CD150 cell surface expression. From other side we attempted to regulate TFs expression via CD150 and CD180 cell surface receptors.

MATERIALS AND METHODS

Studies were performed on normal peripheral blood B-cell subpopulations and chronic lymphocytic leukemia (CLL) cells isolated from peripheral blood of 67 primary untreated patients with CLL. Evaluation of TFs expression was performed on mRNA level using qRT-PCR and on protein level by western blot analysis.

RESULTS

Median of PAX5 and EBF1 mRNA expression was higher in cell surface CD150 positive (csCD150⁺) compared to csCD150^- CLL cases or normal CD19⁺ and CD19⁺CD5⁺ B-cell subsets. Differences in mRNA expression of IRF8, IRF4 and BLIMP1 between studied groups of CLL and normal B cells were not revealed. All CLL cases were characterized by downregulated expression of PU.1 and BCL6 mRNAs in comparison to normal B cells. At the same time elevated SPIB mRNA expression level was restricted to CLL cells. Protein expression of IRF4, IRF8 and BCL6 was uniformly distributed between csCD150^- and csCD150⁺ CLL cases. PU.1 protein and CD20 that is direct PU.1 target gene positively correlated with CD150 cell surface expression on CLL cells. Ligation of CD150 and CD180 alone or in combination upregulated IRF8 and PU.1 while downregulated the IRF4 mRNA expression. Signaling via CD150 or CD180 alone elevated the level of BCL6 mRNA. Strong downregulation of IRF4 mRNA was observed after CD150, CD180 or CD150 andCD180 coligation on CLL cells. We found that in CLL cells CD150 is a negative regulator of SPIB while CD180 is involved in upregulation of EBF1 expression level. Moreover, CD180 ligation on CLL cells caused increase of CD150 mRNA level that is a one of the EBF1 target genes.

CONCLUSIONS

Analysis of TFs expression profile revealed upregulated SPIB mRNA level and downregulated PU.1 in CLL cells. CD150 and CD180 receptors may modulate transcriptional program in CLL cells by regulating the TFs expression levels.

TGF-β1 expression by glioma C6 cells in vitro

The aim of the work was to study the impact of fetal rat brain cell supernatant (FRBCS) on the expression of transforming growth factor β1 (TGF-β1) and p53 in C6 cells of rat glioma in vitro.

MATERIALS AND METHODS

FRBCS was obtained from suspensions of fetal rat brain cells on the 14^th (E14) day of gestation. C6 glioma cells were cultured for 48 h in the presence of FRBCS or FRBCS + anti-TGF-β1 monoclonal antibody. Immunocytochemical staining for TGF-β1 and p53 was performed.

RESULTS

The proportion of TGF-β1-immunopositive tumor cells in C6 glioma cultures was statistically significantly higher than in the control cell cultures of normal fetal rat brain. FRBCS reduced the proportion of TGF-β1-immunopositive tumor cells and increased the proportion of p53-immunopositive cells in C6 glioma cultures. In cells cultured with FRBCS + anti-TGF-β1 monoclonal antibody, the above effects of FRBCS were abrogated.

CONCLUSION

The obtained results suggest that TGF-β1 seems to be responsible for decrease in TGF-β1 expression and increase in p53 expression in C6 glioma cells treated with FRBCS.

Expression Levels of the Uridine-Cytidine Kinase Like-1 Protein As a Novel Prognostic Factor for Hepatitis C VirusAssociated Hepatocellular Carcinomas

The expression levels of the two novel oncoproteins uridine-cytidine kinase like-1 (UCKL-1) and mitochondrial ribosomal protein S18-2 (MRPS18-2) were assessed in samples of hepatitis C virus (HCV)-associated hepatocellular carcinoma (HCC) using immunohistochemistry. Tissue microarray (TMA) paraffin blocks were prepared from 42 HCC tumor samples with the corresponding peri-tumor tissues and from 11 tissues of a liver with HCV-induced cirrhosis. We found that the UCKL-1 signal in the liver tissues of the peri-tumor zone in the HCC samples was stronger than that in cirrhosis (50 49.44 vs. 24.27 14.53; p = 0.014). The MRPS18-2 expression was weak, and there was no differences between the groups (p = 0.26). Noteworthy, the UCKL-1 protein was expressed at higher levels in peri-tumor tissues in the cases of HCC recurrence; this was confirmed for 27 older patients (63.78 9.22 vs. 53.53 4.07 years, p 0.001), in parallel with enhanced UCKL-1 staining in former HCC nodules (62.69 50.4 vs. 26.0 30.19, p = 0.006) and microvascular invasion (p = 0.02). A multivariate analysis of prognostic factors for HCC recurrence showed that the best predictive factors for these conditions were UCKL-1 expression in tumor, vascular invasion, and HCC treatment modality, other than liver transplantation (odds ratios: 1.029, 18.143 and 11.984, R = 0.633, p = 0.002). In conclusion, the high UCKL-1 expression might be a prognostic factor for HCC relapse, in combination with age and microvascular invasion. MRPS18-2 protein expression has no prognostic significance in the cases of HCV-associated HCC.

Expression Levels of the Uridine-Cytidine Kinase Like-1 Protein As a Novel Prognostic Factor for Hepatitis C Virus-Associated Hepatocellular Carcinomas

The expression levels of the two novel oncoproteins uridine-cytidine kinase like-1 (UCKL-1) and mitochondrial ribosomal protein S18-2 (MRPS18-2) were assessed in samples of hepatitis C virus (HCV)-associated hepatocellular carcinoma (HCC) using immunohistochemistry. Tissue microarray (TMA) paraffin blocks were prepared from 42 HCC tumor samples with the corresponding peri-tumor tissues and from 11 tissues of a liver with HCV-induced cirrhosis. We found that the UCKL-1 signal in the liver tissues of the peri-tumor zone in the HCC samples was stronger than that in cirrhosis (50 ± 49.44 vs. 24.27 ± 14.53; p = 0.014). The MRPS18-2 expression was weak, and there was no differences between the groups (p = 0.26). Noteworthy, the UCKL-1 protein was expressed at higher levels in peri-tumor tissues in the cases of HCC recurrence; this was confirmed for 27 older patients (63.78 ± 9.22 vs. 53.53 ± 4.07 years, p < 0.001), in parallel with enhanced UCKL-1 staining in former HCC nodules (62.69 ± 50.4 vs. 26.0 ± 30.19, p = 0.006) and microvascular invasion (p = 0.02). A multivariate analysis of prognostic factors for HCC recurrence showed that the best predictive factors for these conditions were UCKL-1 expression in tumor, vascular invasion, and HCC treatment modality, other than liver transplantation (odds ratios: 1.029, 18.143 and 11.984, R² = 0.633, p = 0.002). In conclusion, the high UCKL-1 expression might be a prognostic factor for HCC relapse, in combination with age and microvascular invasion. MRPS18-2 protein expression has no prognostic significance in the cases of HCV-associated HCC.

Mitochondrial ribosomal protein S18-2 evokes chromosomal instability and transforms primary rat skin fibroblasts

We have shown earlier that overexpression of the human mitochondrial ribosomal protein MRPS18-2 (S18-2) led to immortalization of primary rat embryonic fibroblasts. The derived cells expressed the embryonic stem cell markers, and cellular pathways that control cell proliferation, oxidative phosphorylation, cellular respiration, and other redox reactions were activated in the immortalized cells.Here we report that, upon overexpression of S18-2 protein, primary rat skin fibroblasts underwent cell transformation. Cells passed more than 300 population doublings, and two out of three tested clones gave rise to tumors in experimental animals. Transformed cells showed anchorage-independent growth and loss of contact inhibition; they expressed epithelial markers, such as E-cadherin and β-catenin. Transformed cells showed increased telomerase activity, disturbance of the cell cycle, and chromosomal instability. Taken together, our data suggest that S18-2 is a newly identified oncoprotein that may be involved in cancerogenesis.

Expression of CD150 in tumors of the central nervous system: identification of a novel isoform

CD150 (IPO3/SLAM) belongs to the SLAM family of receptors and serves as a major entry receptor for measles virus. CD150 is expressed on normal and malignant cells of the immune system. However, little is known about its expression outside the hematopoietic system, especially tumors of the central nervous system (CNS). Although CD150 was not found in different regions of normal brain tissues, our immunohistochemical study revealed its expression in 77.6% of human CNS tumors, including glioblastoma, anaplastic astrocytoma, diffuse astrocytoma, ependymoma, and others. CD150 was detected in the cytoplasm, but not on the cell surface of glioma cell lines, and it was colocalized with the endoplasmic reticulum and Golgi complex markers. In addition to the full length mRNA of the mCD150 splice isoform, in glioma cells we found a highly expressed novel CD150 transcript (nCD150), containing an 83 bp insert. The insert is derived from a previously unrecognized exon designated Cyt-new, which is located 510 bp downstream of the transmembrane region exon, and is a specific feature of primate SLAMF1. Both mCD150 and nCD150 cDNA variants did not contain any mutations and had the leader sequence. The nCD150 transcript was also detected in normal and malignant B lymphocytes, primary T cells, dendritic cells and macrophages; however, in glioma cells nCD150 was found to be the predominant CD150 isoform. Similarly to mCD150, cell surface expression of nCD150 allows wild type measles virus entry to the cell. Our data indicate that CD150 expression in CNS tumors can be considered a new diagnostic marker and potential target for novel therapeutic approaches.