A deep intronic recurrent CHEK2 variant c.1009-118_1009-87delinsC affects pre-mRNA splicing and contributes to hereditary breast cancer predisposition.

Germline CHEK2 pathogenic variants confer an increased risk of female breast cancer (FBC). Here we describe a recurrent germline intronic variant c.1009-118_1009-87delinsC, which showed a splice acceptor shift in RNA analysis, introducing a premature stop codon (p.Tyr337PhefsTer37). The variant was found in 21/10,204 (0.21%) Czech FBC patients compared to 1/3250 (0.03%) controls (p = 0.04) and in 4/3639 (0.11%) FBC patients from an independent German dataset. In addition, we found this variant in 5/2966 (0.17%) Czech (but none of the 443 German) ovarian cancer patients, three of whom developed early-onset tumors. Based on these observations, we classified this variant as likely pathogenic.

Challenges of in situ hybridization in miRNA analysis of triple-negative breast cancer morphological diversity.

miRNA expression in triple-negative breast cancers (TNBC) has mainly been studied from a methodological viewpoint. However, it has not been considered that miRNA expression profile may be associated with a specific morphological entity inside every tumor. The verification of this hypothesis on a set of 25 TNBCs was the subject of our previous work, where we confirmed specific expression of the studied miRNAs in 82 samples of different morphologies including inflammatory infiltrate, spindle cell, clear cell, and metastases after RNA extraction and purification as well as microchip and biostatistical analysis. In the current work, we demonstrate a low suitability of in situ hybridization method for miRNA detection compared to RT-qPCR, and in detail discuss the biological role of 8 miRNAs with the most significant changes of expression.

Ovarian tumors and genetic predisposition.

OBJECTIVE: Summary of knowledge in the field of ovarian cancer and genetic predisposition. RESULTS: Ovarian tumors are usually diagnosed at advanced stages of the disease and the prognosis for these patients is generally poor. The 5-year overall survival rate, regardless of the histopathological type of tumor, is around 44%. Germline mutations causing hereditary tumor syndromes are predominantly involved in the development of epithelial ovarian tumors. The most common is hereditary breast and ovarian cancer syndrome, which is caused by germline mutations in the tumor suppressor genes BRCA1 and BRCA2. Several other tumor suppressor genes and oncogenes are known to be associated with ovarian tumors and cause other types of tumor syndromes. Inherited tumor syndromes include Lynch syndrome, Peutz-Jegers syndrome, Gorlin syndrome, Li-Fraumeni syndrome and others. The indication for genetic examination of germline mutations is given by a clinical geneticist on the basis of the recommendation of the attending physician. At present, every ovarian tumor, primary peritoneal tumor and tube tumor diagnosed at any age is indicated for genetic testing. CONCLUSION: Early identification of genes for hereditary cancer syndromes, thanks to rapidly developing molecular genetic methods, is an important step towards personalized treatment of ovarian cancer and preventive measures in families at risk. It is also important to note that a negative molecular genetic test result does not exclude genetic risk.

Epithelial to mesenchymal transition and microRNA expression are associated with spindle and apocrine cell morphology in triple-negative breast cancer.

Triple negative breast cancers (TNBC) are a morphologically and genetically heterogeneous group of breast cancers with uncertain prediction of biological behavior and response to therapy. Epithelial to mesenchymal transition (EMT) is a dynamic process characterized by loss of typical epithelial phenotype and acquisition of mesenchymal characteristics. Aberrant activation of EMT can aggravate the prognosis of patients with cancer, however, the mechanisms of EMT and role of microRNAs (miRNAs) in EMT activation is still unclear. The aim of our study was to analyze miRNA expression within areas of TNBCs with cellular morphology that may be related to the EMT process and discuss possible associations. Out of all 3953 re-examined breast cancers, 460 breast cancers were diagnosed as TNBC (11.64%). With regard to complete tumor morphology preservation, the tissue samples obtained from core-cut biopsies and influenced by previous neoadjuvant therapy were excluded. We assembled a set of selected 25 cases to determine miRNA expression levels in relation to present focal spindle cell and apocrine cell morphology within individual TNBCs. We used descriptive (histological typing and morphology), morphometric, molecular (microdissection of tumor and non-tumor morphologies, RNA isolation and purification, microchip analysis) and bioinformatic analysis (including pathway analysis). The results were verified by quantitative real-time PCR (RT-qPCR) on an extended set of 70 TNBCs. The majority of TNBCs were represented by high-grade invasive carcinomas of no special type (NST) with medullary features characterized by well-circumscribed tumors with central necrosis or fibrosis and frequent tendency to spindle-cell and/or apocrine cell transformation. Apocrine and spindle cell transformation showed a specific miRNA expression profile in comparison to other tumor parts, in situ carcinoma or non-tumor structures, particularly down-regulated expression of hsa-miRNA-143-3p and hsa-miRNA-205-5p and up-regulated expression of hsa-miR-22-3p, hsa-miRNA-185-5p, and hsa-miR-4443. Apocrine cell tumor morphology further revealed decreased expression of hsa-miR-145-5p and increased expression of additional 14 miRNAs (e.g. hsa-miR-182-5p, hsa-miR-3135b and hsa-miR-4417). Pathway analysis for target genes of these miRNAs revealed several shared biological processes (i.e. Wnt signaling, ErbB signaling, MAPK signaling, endocytosis and axon guidance), which may in part contribute to the EMT and tumor progression. We provide the first miRNA expression profiling of specific tissue morphologies in TNBC. Our results demonstrate a specific miRNA expression profile of apocrine and spindle cell morphology which can exhibit a certain similarity with the EMT process and may also be relevant for prognosis and therapy resistance of TNBC.

Sphingosine kinase-1 predicts overall survival outcomes in non-small cell lung cancer patients treated with carboplatin and navelbine.

Sphingosine 1-phosphate (S1P) is a bioactive lipid metabolite associated with cancer cell proliferation, survival, migration and regulation of tumor angiogenesis in various cellular and animal models. Sphingosine kinase-1 (SphK1) and S1P lyase are the main enzymes that respectively control the synthesis and degradation of S1P. The present study analyzed the prognostic and predictive value of SphK1 and S1P lyase expression in patients with non-small cell lung cancer (NSCLC), treated with either surgery alone or in combination with adjuvant carboplatin and navelbine. Formalin-fixed, paraffin-embedded tissue samples from 176 patients with NSCLC were stained immunohistochemically using antibodies against SphK1 and S1P lyase, and their expression was correlated with all available clinicopathological factors. Increased expression of SphK1 was significantly associated with shorter overall and disease free survival in patients treated with adjuvant platinum-based chemotherapy. No prognostic relevance for S1P lyase expression was observed. Collectively, the results suggest that the immunohistochemical detection of SphK1 may be a promising predictive marker in NSCLC patients treated with adjuvant platinum-based chemotherapy.

Serum C-peptide level correlates with the course of muscle tissue healing in the rabbit model of critical limb ischemia.

AIM: The therapeutic potential of adipose-derived stem cell conditioned medium (ASC-CM) was studied in the rabbit model of critical limb ischemia (CLI). METHODS: Rabbits received treatment with ASC-CM or placebo. Gastrocnemius muscle tissue was collected 35 days after ischemia induction. Ischemic changes were evaluated in hematoxylin-eosin stained tissues for early (necrotic lesions/granulation tissue) and late (fibrous scars) phases of tissue repair. The expression of proangiogenic miR-126 was also evaluated using in situ hybridization. The levels of cytokines, insulin, and C-peptide were measured in blood. RESULTS: Early repair phases were observed more often in placebo-treated samples (45.5%) than in ASC-CM-treated ones (22.2%). However, the difference was not statistically significant. We demonstrated a statistically significant positive correlation between the early healing phases in tissue samples and C-peptide levels in peripheral blood. The expression of proangiogenic miR-126 was also shown in a number of structures in all phases of ischemic tissue healing. CONCLUSION: Based on our results, we believe that treatment with ASC-CM has the potential to accelerate the healing process in ischemic tissues in the rabbit model of CLI. The whole healing process was accompanied by miR-126 tissue expression. C-peptide could be used to monitor the course of the tissue healing process.

The Role of miR-126 in Critical Limb Ischemia Treatment Using Adipose-Derived Stem Cell Therapeutic Factor Concentrate and Extracellular Matrix Microparticles.

BACKGROUND Paracrine factors secreted by adipose-derived stem cells can be captured, fractionated, and concentrated to produce therapeutic factor concentrate (TFC). The present study examined whether TFC effects could be enhanced by combining TFC with a biological matrix to provide sustained release of factors in the target region. MATERIAL AND METHODS Unilateral hind limb ischemia was induced in rabbits. Ischemic limbs were injected with either placebo control, TFC, micronized small intestinal submucosa tissue (SIS), or TFC absorbed to SIS. Blood flow in both limbs was assessed with laser Doppler perfusion imaging. Tissues harvested at Day 48 were assessed immunohistochemically for vessel density; in situ hybridization and quantitative real-time PCR were employed to determine miR-126 expression. RESULTS LDP ratios were significantly elevated, compared to placebo control, on day 28 in all treatment groups (p=0.0816, p=0.0543, p=0.0639, for groups 2-4, respectively) and on day 36 in the TFC group (p=0.0866). This effect correlated with capillary density in the SIS and TFC+SIS groups (p=0.0093 and p=0.0054, respectively, compared to placebo). A correlation was observed between miR-126 levels and LDP levels at 48 days in SIS and TFC+SIS groups. CONCLUSIONS A single bolus administration of TFC and SIS had early, transient effects on reperfusion and promotion of ischemia repair. The effects were not additive. We also discovered that TFC modulated miR-126 levels that were expressed in cell types other than endothelial cells. These data suggested that TFC, alone or in combination with SIS, may be a potent therapy for patients with CLI that are at risk of amputation.

Single giant mediastinal rhabdomyoma as a sole manifestation of TSC in foetus.

BACKGROUND: Presence of multiple cardiac rhabdomyomas is one of the major features of Tuberous sclerosis (TSC), but isolated progressing single giant rhabdomyoma is very rare and not typical of TSC. CASE REPORT: This report presents family without obvious history of TSC with occurrence of giant mediastinal rhabdomyoma affecting the haemodynamics in male foetus, without other TSC symptoms. Girl from the next gravidity had prenatally detected multiple rhabdomyomas and small subcortical tuber of brain detected after birth. DNA analysis found novel c.4861A>T TSC2 variant and large deletion in TSC2 in tumour tissue from male foetus. The novel TSC2 variant was also present in the girl and her healthy father, in silico analysis suggested its functional effect on TSC2. Brain MRI of the father detected mild TSC specific abnormality. CONCLUSION: We suggest the novel TSC2 mutation is a cause of mild TSC in this family and has reduced expression. The clinical and molecular findings in this family also emphasize that TSC diagnosis should be also evaluated in case of single giant foetal cardiac rhabdomyoma.

The dual role of asporin in breast cancer progression.

Asporin has been reported as a tumor suppressor in breast cancer, while asporin-activated invasion has been described in gastric cancer. According to our in silico search, high asporin expresion associates with significantly better relapse free survival (RFS) in patients with low-grade tumors but RFS is significantly worse in patients with grade 3 tumors. In line with other studies, we have confirmed asporin expression by RNA scope in situ hybridization in cancer associated fibroblasts. We have also found asporin expression in the Hs578T breast cancer cell line which we confirmed by quantitative RT-PCR and western blotting. From multiple testing, we found that asporin can be downregulated by bone morphogenetic protein 4 while upregulation may be facilited by serum-free cultivation or by three dimensional growth in stiff Alvetex scaffold. Downregulation by shRNA inhibited invasion of Hs578T as well as of CAFs and T47D cells. Invasion of asporin-negative MDA-MB-231 and BT549 breast cancer cells through collagen type I was enhanced by recombinant asporin. Besides other investigations, large scale analysis of aspartic acid repeat polymorphism will be needed for clarification of the asporin dual role in progression of breast cancer.

Clinical Potential of Effective Noninvasive Exclusion of KEL1-Positive Fetuses in KEL1-Negative Pregnant Women.

BACKGROUND: The clinical importance of assessing the fetal KEL genotype is to exclude 'K'-positive fetuses (genotype KEL1/KEL2) in 'K'-alloimmunized pregnant women (genotype KEL2/KEL2). Noninvasive assessment of the fetal KEL genotype is not yet available in the Czech Republic. OBJECTIVE: The aim of this study was to assess the fetal KEL1/KEL2 genotype from cell-free fetal DNA in the plasma of KEL2/KEL2 pregnant women. METHODS: The fetal genotype was assessed by minisequencing (a dilution series including control samples). A total of 138 pregnant women (between the 8th and 23rd gestational week) were tested by minisequencing. The fetal genotype was further verified by analysis of a buccal swab from the newborn. RESULTS: Minisequencing proved to be a reliable method. In 2.2% (3/138) of the examined women, plasma sample testing failed; 94.8% (128/135) had the KEL2/KEL2 genotype, and a total of 3.1% of fetuses (4/128) had the KEL1/KEL2 genotype. Sensitivity and specificity reached 100% (p < 0.0001). CONCLUSION: Minisequencing is a reliable method for the assessment of the fetal KEL1 allele from the plasma of KEL2/KEL2 pregnant women.

High expression of the RNA-binding protein RBPMS2 in gastrointestinal stromal tumors.

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal neoplasms of the gastrointestinal tract and are often associated with KIT or PDGFRA gene mutations. GIST cells might arise from the interstitial cells of Cajal (ICCs) or from a mesenchymal precursor that is common to ICCs and smooth muscle cells (SMCs). Here, we analyzed the mRNA and protein expression of RNA-Binding Protein with Multiple Splicing-2 (RBPMS2), an early marker of gastrointestinal SMC precursors, in human GISTs (n=23) by in situ hybridization, quantitative RT-PCR analysis and immunohistochemistry. The mean RBPMS2 mRNA level in GISTs was 42-fold higher than in control gastrointestinal samples (p<0.001). RBPMS2 expression was not correlated with KIT and PDGFRA expression levels, but was higher in GISTs harboring KIT mutations than in tumors with wild type KIT and PDGFRA or in GISTs with PDGFRA mutations that were characterized by the lowest RBPMS2 levels. Moreover, RBPMS2 levels were 64-fold higher in GIST samples with high risk of aggressive behavior than in adult control gastrointestinal samples and 6.2-fold higher in high risk than in low risk GIST specimens. RBPMS2 protein level was high in 87% of the studied GISTs independently of their histological classification. Finally, by inhibiting the KIT signaling pathway in GIST882 cells, we show that RBPMS2 expression is independent of KIT activation. In conclusion, RBPMS2 is up-regulated in GISTs compared to normal adult gastrointestinal tissues, indicating that RBPMS2 might represent a new diagnostic marker for GISTs and a potential target for cancer therapy.

Analysis of the prognostic impact of nestin expression in non-small cell lung cancer.

BACKGROUND: Nestin is an intermediary filament protein, expressed in progenitor cells of neural and muscle origin and in activated endothelium. The expression of this protein in tumours can be associated with degree of differentiation, biological potential and/or neoangiogenesis. AIMS: The aim of this study was to examine the immunohistochemical expression of nestin in primary non-small cell lung carcinomas (NSCLC) and to determine its prognostic significance. METHODS: Immunohistochemical detection of nestin was carried out on tissue microarrays constructed from 114 formalin-fixed and paraffin-embedded NSCLC samples. These included 78 squamous cell carcinomas and 37 adenocarcinomas. Expression of nestin was also analysed in 35 primary tumour independent NSCLC brain metastasis. The H-score and degree of nestin positive microvascularisation were determined. Both parameters correlated with the clinicopathological characteristics including disease-free and overall survival. Results. We demonstrated that expression of nestin is not significantly higher in tumour cells of adenocarcinomas than in sqamous cell carcinomas despite the fact that adenocarcinomas were more frequently positive (P≤0.30). On the other hand, nestin positivity and nestin positive neovascularisation were significantly more often found in stage IIIa tumours than tumours in stages I and II (P≤0.04, P≤0.02). Nestin expression was also significantly higher in brain metastases of squamous cell carcinomas than brain metastases of adenocarcinomas (P≤0.003). The expression of nestin, in general, did not significantly correspond to disease-free or overall survival. CONCLUSION: Nestin expression in NSCLCs is associated with poorer prognosis and with greater nestin-positive microvessel density.

Identification of CD133+/nestin+ putative cancer stem cells in non-small cell lung cancer.

AIMS: No effective treatment for lung cancer exists currently. One reason for this, is the development of drug resistance, assumed to be associated with cancer stem cell (CSCs) emergence within the tumour. This pilot study aimed to identify CSCs in 121 non-small cell lung cancer (NSCLC) patient samples via detection of the expression of stem cell markers - CD133 and nestin. MATERIAL AND METHODS: Archived paraffin blocks of 121 patient samples were prepared as Tissue Microarrays (TMA). Indirect immunohistochemical staining was used to determine the level of expression of CD133 and nestin. Double immunofluorescence staining was used to investigate the co-expression of these two markers. To determine the correlation between expression of nestin and CD133 with the length of asymptomatic period and overall patient survival we used the Kaplan-Meyer analysis. RESULTS: CD133 expression was detected in 22 (19%), nestin in the epithelium in 74 (66%) and vasculature in 78 (70%) of patients. Co-expression of these two markers was found in 21 (17%) patients in less than 1% of positive cells without impact on disease free or overall survival. CONCLUSIONS: We identified CD133(+)/nestin(+) cells as novel potential markers of lung cancer CSCs.