Bacterial communities along parrot digestive and respiratory tracts: the effects of sample type, species and time.

Digestive and respiratory tracts are inhabited by rich bacterial communities that can vary between their different segments. In comparison with other bird taxa with developed caeca, parrots that lack caeca have relatively lower variability in intestinal morphology. Here, based on 16S rRNA metabarcoding, we describe variation in microbiota across different parts of parrot digestive and respiratory tracts both at interspecies and intraspecies levels. In domesticated budgerigar (Melopsittacus undulatus), we describe the bacterial variation across eight selected sections of respiratory and digestive tracts, and three non-destructively collected sample types (faeces, and cloacal and oral swabs). Our results show important microbiota divergence between the upper and lower digestive tract, but similarities between respiratory tract and crop, and also between different intestinal segments. Faecal samples appear to provide a better proxy for intestinal microbiota composition than the cloacal swabs. Oral swabs had a similar bacterial composition as the crop and trachea. For a subset of tissues, we confirmed the same pattern also in six different parrot species. Finally, using the faeces and oral swabs in budgerigars, we revealed high oral, but low faecal microbiota stability during a 3-week period mimicking pre-experiment acclimation. Our findings provide a basis essential for microbiota-related experimental planning and result generalisation in non-poultry birds.

FoxO1-GAB1 axis regulates homing capacity and tonic AKT activity in chronic lymphocytic leukemia.

Recirculation of chronic lymphocytic leukemia (CLL) cells between the peripheral blood and lymphoid niches plays a critical role in disease pathophysiology, and inhibiting this process is one of the major mechanisms of action for B-cell receptor (BCR) inhibitors such as ibrutinib and idelalisib. Migration is a complex process guided by chemokine receptors and integrins. However, it remains largely unknown how CLL cells integrate multiple migratory signals while balancing survival in the peripheral blood and the decision to return to immune niches. Our study provided evidence that CXCR4/CD5 intraclonal subpopulations can be used to study the regulation of migration of CLL cells. We performed RNA profiling of CXCR4dimCD5bright vs CXCR4brightCD5dim CLL cells and identified differential expression of dozens of molecules with a putative function in cell migration. GRB2-associated binding protein 1 (GAB1) positively regulated CLL cell homing capacity of CXCR4brightCD5dim cells. Gradual GAB1 accumulation in CLL cells outside immune niches was mediated by FoxO1-induced transcriptional GAB1 activation. Upregulation of GAB1 also played an important role in maintaining basal phosphatidylinositol 3-kinase (PI3K) activity and the "tonic" AKT phosphorylation required to sustain the survival of resting CLL B cells. This finding is important during ibrutinib therapy, because CLL cells induce the FoxO1-GAB1-pAKT axis, which represents an adaptation mechanism to the inability to home to immune niches. We have demonstrated that GAB1 can be targeted therapeutically by novel GAB1 inhibitors, alone or in combination with BTK inhibition. GAB1 inhibitors induce CLL cell apoptosis, impair cell migration, inhibit tonic or BCR-induced AKT phosphorylation, and block compensatory AKT activity during ibrutinib therapy.

miR-29 modulates CD40 signaling in chronic lymphocytic leukemia by targeting TRAF4: an axis affected by BCR inhibitors.

B-cell receptor (BCR) signaling and T-cell interactions play a pivotal role in chronic lymphocytic leukemia (CLL) pathogenesis and disease aggressiveness. CLL cells can use microRNAs (miRNAs) and their targets to modulate microenvironmental interactions in the lymph node niches. To identify miRNA expression changes in the CLL microenvironment, we performed complex profiling of short noncoding RNAs in this context by comparing CXCR4/CD5 intraclonal cell subpopulations (CXCR4dimCD5bright vs CXCR4brightCD5dim cells). This identified dozens of differentially expressed miRNAs, including several that have previously been shown to modulate BCR signaling (miR-155, miR-150, and miR-22) but also other candidates for a role in microenvironmental interactions. Notably, all 3 miR-29 family members (miR-29a, miR-29b, miR-29c) were consistently down-modulated in the immune niches, and lower miR-29(a/b/c) levels associated with an increased relative responsiveness of CLL cells to BCR ligation and significantly shorter overall survival of CLL patients. We identified tumor necrosis factor receptor-associated factor 4 (TRAF4) as a novel direct target of miR-29s and revealed that higher TRAF4 levels increase CLL responsiveness to CD40 activation and downstream nuclear factor-κB (NF-κB) signaling. In CLL, BCR represses miR-29 expression via MYC, allowing for concurrent TRAF4 upregulation and stronger CD40-NF-κB signaling. This regulatory loop is disrupted by BCR inhibitors (bruton tyrosine kinase [BTK] inhibitor ibrutinib or phosphatidylinositol 3-kinase [PI3K] inhibitor idelalisib). In summary, we showed for the first time that a miRNA-dependent mechanism acts to activate CD40 signaling/T-cell interactions in a CLL microenvironment and described a novel miR-29-TRAF4-CD40 signaling axis modulated by BCR activity.

Practices of Care in Participatory Design With Older Adults During the COVID-19 Pandemic: Digitally Mediated Study.

BACKGROUND: Participatory Design (PD), albeit an established approach in User-Centered Design, comes with specific challenges when working with older adults as research participants. Addressing these challenges relates to the reflection and negotiation of the positionalities of the researchers and research participants and includes various acts of giving and receiving help. During the COVID-19 pandemic, facets of positionalities and (mutual) care became particularly evident in qualitative and participatory research settings. OBJECTIVE: The aim of this paper was to systematically analyze care practices of participatory (design) research, which are to different extents practices of the latter. Using a multiyear PD project with older people that had to take place remotely over many months, we specify different practices of care; how they relate to collaborative work in the design project; and represent foundational practices for sustainable, long-term co-design. Our research questions were "How can digitally-mediated PD work during COVID-19 and can we understand such digital PD as 'care'?" METHODS: Our data comes from the Joint Programming Initiative "More Years, Better Lives" (JPI MYBL), a European Union project that aims to promote digital literacy and technology appropriation among older adults in domestic settings. It targeted the cocreation, by older adults and university researchers, of a mobile demo kit website with cocreated resources, aimed at improving the understanding of use options of digital tools. Through a series of workshops, a range of current IT products was explored by a group of 21 older adults, which served as the basis for joint cocreative work on generating design ideas and prototypes. We reflect on the PD process and examine how the actors enact and manifest care. RESULTS: The use of digital technology allowed the participatory project to continue during the COVID-19 pandemic and accentuated the digital skills of older adults and the improvement of digital literacy as part of "care." We provide empirically based evidence of PD with older adults developing digital literacy and sensitizing concepts, based on the notion of care by Tronto for differentiating aspects and processes of care. The data suggest that it is not enough to focus solely on the technologies and how they are used; it is also necessary to focus on the social structures in which help is available and in which technologies offer opportunities to do care work. CONCLUSIONS: We document that the cocreation of different digital media tools can be used to provide a community with mutual care. Our study demonstrates how research participants effectively enact different forms of care and how such "care" is a necessary basis for a genuinely participatory approach, which became especially meaningful as a form of support during COVID-19. We reflect on how notions of "care" and "caring" that were central to the pandemic response are also central to PD.

Survivability and proliferation of microorganisms in bentonite with implication to radioactive waste geological disposal: strong effect of temperature and negligible effect of pressure.

As bentonite hosts a diverse spectrum of indigenous microorganisms with the potential to influence the long-term stability of deep geological repositories, it is essential to understand the factors influencing microbial activity under repository conditions. Here, we focus on two factors, i.e., temperature and swelling pressure, using a suspension of Cerny Vrch bentonite to boost microbial activity and evaluate microbial response. Suspensions were exposed either to different pressures (10, 12 and 15 MPa; to simulate the effect of swelling pressure) or elevated temperatures (60, 70, 80 and 90 °C; to simulate the effect of cannister heating) for four weeks. Each treatment was followed by a period of anaerobic incubation at atmospheric pressure/laboratory temperature to assess microbial recovery after treatment. Microbial load and community structure were then estimated using molecular-genetic methods, with presence of living cells confirmed through microscopic analysis. Our study demonstrated that discrete application of pressure did not influence on overall microbial activity or proliferation, implying that pressure evolution during bentonite swelling is not the critical factor responsible for microbial suppression in saturated bentonites. However, pressure treatment caused significant shifts in microbial community structure. We also demonstrated that microbial activity decreased with increasing temperature, and that heat treatment strongly influenced bentonite microbial community structure, with several thermophilic taxa identified. A temperature of 90 °C proved to be limiting for microbial activity and proliferation in all bentonite suspensions. Our study emphasizes the crucial role of a deep understanding of microbial activity under repository-relevant conditions in identifying possible strategies to mitigate the microbial potential within the deep geological repository and increase its long-term stability and safety.

Methylation analysis as an auxiliary tool in cytological diagnostics of infrequent anogenital lesions - a pilot study.

Methylation silencing of certain cellular genes is a sign of carcinogenesis progression and therefore tests that detect methylation could be used in the diagnosis or staging of malignant diseases. In the diagnosis of squamous cell carcinomas of the cervix which are almost 100% caused by long-term infection with highrisk human papillomavirus (HR-HPV), methylation silencing of certain cellular genes is a highly specific marker of advanced dysplastic lesions and appears to result from aberrant activation of the methyltransferase DNMT1 by viral oncoproteins E6 and E7. A methylation test performed on a cervicovaginal cytology specimen allows to increase the diagnostic value of this non-invasive test and to select patients with severe squamous cell lesions for follow-up. Other less frequent anogenital malignancies that are induced by HR-HPV to a lesser extent can also be detected by cytological examination - glandular lesions of various origins, most commonly cervical and endometrial adenocarcinomas and anal carcinoma. The aim of our pilot study was to evaluate the utility of a methylation test for the diagnosis of these malignancies in a cohort of 50 liquid-based cervicovaginal cytologies with glandular lesion and 74 liquid-based anal cytologies from HIV-positive men having sex with men who are at high risk for anal cancer development.

Intestinal mycobiome associated with diagnosis of inflammatory bowel disease based on tissue biopsies.

Analysis of mycobiome from formalin-fixed, paraffin-embedded (FFPE) biopsies should preferentially detect only fungi which are actually present in the intestine wall, in contrast to stool samples, which are limited by the diet composition. Next generation sequencing provides the advantage of analyzing many species from a single sample. Consequently, canonical correspondence analysis divided fungal genera present in FFPE intestinal tissues into three well-defined experimental groups (negative controls - NC, Crohn's disease - CD, ulcerative colitis - UC). Simultaneously, the analysis showed that particular fungal genera are associated with these experimental groups and several fungal genera occurred in all experimental groups equally. Our results also showed a noticeable increase of Ascomycota proportion from NC, through CD to UC. Fungal genera Malassezia, Cladosporium and Toninia occurred in all experimental groups assuming that they are common components of the intestinal mycobiome. Other fungal genera found only in the NC experimental group were non-pathogenic and might bring some benefits. In contrast, CD and UC samples were characterized by an accumulation of genera with inhibitive effects on growth of other fungal genera and the presence of opportunistic pathogens. Furthermore, a decrease in the fungal genus Malassezia in inflammatory tissues was observed; Specifically, the UC experimental group showed a connection between the presence of Candida and seven time's lower amounts of Malassezia (compared to amounts found in NC). The CD experimental group was characterized by the simultaneous presence of Engyodontium album with Lecanicillium, and indicates a possible pathogenic effect of Ramularia in disease development. LAY SUMMARY: Mycobiome analysis of formalin-fixed and paraffin-embedded biopsies may highlight actual fungal genera composition in the intestinal wall. Interestingly, experimental groups of Crohn's disease and ulcerative colitis clearly differed by structure of their mycobiomes.

Polyandrous bee provides extended offspring care biparentally as an alternative to monandry based eusociality.

Parental care behavior evolves to increase the survival of offspring. When offspring care becomes complicated for ecological reasons, cooperation of multiple individuals can be beneficial. There are two types of cooperative care: biparental care and worker (helper)-based care (e.g., eusociality). Although biparental care is common in several groups of vertebrates, it is generally rare in arthropods. Conversely, eusociality is widespread in insects, especially the aculeate Hymenoptera. Here, we present a case of biparental care in bees, in Ceratina nigrolabiata (Apidae, Xylocopinae). Similar to eusocial behavior, biparental care leads to greater brood protection in this species. Male guarding increases provisioning of nests because females are liberated from the tradeoff between provisioning and nest protection. The main benefit of parental care for males should be increased paternity. Interestingly though, we found that paternity of offspring by guard males is extraordinarily low (10% of offspring). Generally, we found that nests were not guarded by the same male for the whole provisioning season, meaning that males arrive to nests as stepfathers. However, we show that long-term guarding performed by a single male does increase paternity. We suggest that the multiple-mating strategy of these bees increased the amount of time for interactions between the sexes, and this longer period of potential interaction supported the origin of biparental care. Eusociality based on monandry was thought to be the main type of extended brood protection in bees. We show that biparental care based on polyandry provides an interesting evolutionary alternative.

SARS-CoV-2 RNA may rarely be present in a uterine cervix LBC sample at the asymptomatic early stage of COVID 19 disease.

OBJECTIVE: Currently, it is thought that uterine cervix mucosal samples present a low risk of SARS-CoV-2 exposure. So far, there is no evidence of SARS-CoV-2 detection in Papanicolaou (Pap) smears. Nevertheless, clinicians could be exposed unaware to the coronavirus while performing and handling a Pap smear. We aimed to retrospectively evaluate the presence of SARS-CoV-2 RNA in cervical liquid-based cytology (LBC) samples in women who tested positive for a nasopharyngeal COVID-19 PCR test. METHODS: From our laboratory database, we identified patients with data on a cervical cancer screening LBC sample paired with a positive nasopharyngeal COVID-19 PCR test. Relevant LBC samples taken within an incubation period of 14 days and post-onset RNA shedding interval of 25 days were subsequently tested for SARS-CoV-2 RNA using RT-PCR tests. RESULTS: The study group consisted of 102 women. Of those, 23 LBC samples were tested. SARS-CoV-2 RNA was detected in one LBC sample from a 26-year-old asymptomatic woman taken six days before reporting headaches and knee arthralgia with a positive nasopharyngeal SARS-CoV-2 RT-PCR test. CONCLUSIONS: It is possible to detect SARS-CoV-2 RNA in cervical LBC samples at an early asymptomatic stage of COVID-19. In general, this finding is infrequent in asymptomatic women who tested SARS-CoV-2 positive within an incubation of 14 days and a post-onset RNA shedding period of 25 days. We fully support the current thinking that cervical LBC samples from asymptomatic women pose a low risk of SARS-CoV-2 exposure and can be handled in the frame of good microbiological practice and procedures.

miR-150 downregulation contributes to the high-grade transformation of follicular lymphoma by upregulating FOXP1 levels.

Follicular lymphoma (FL) is a common indolent B-cell malignancy with a variable clinical course. An unfavorable event in its course is histological transformation to a high-grade lymphoma, typically diffuse large B-cell lymphoma. Recent studies show that genetic aberrations of MYC or its overexpression are associated with FL transformation (tFL). However, the precise molecular mechanisms underlying tFL are unclear. Here we performed the first profiling of expression of microRNAs (miRNAs) in paired samples of FL and tFL and identified 5 miRNAs as being differentially expressed. We focused on one of these miRNAs, namely miR-150, which was uniformly downmodulated in all examined tFLs (∼3.5-fold), and observed that high levels of MYC are responsible for repressing miR-150 in tFL by binding in its upstream region. This MYC-mediated repression of miR-150 in B cells is not dependent on LIN28A/B proteins, which influence the maturation of miR-150 precursor (pri-miR-150) in myeloid cells. We also demonstrated that low miR-150 levels in tFL lead to upregulation of its target, namely FOXP1 protein, which is a known positive regulator of cell survival, as well as B-cell receptor and NF-κB signaling in malignant B cells. We revealed that low levels of miR-150 and high levels of its target, FOXP1, are associated with shorter overall survival in FL and suggest that miR-150 could serve as a good biomarker measurable in formalin-fixed paraffin-embedded tissue. Overall, our study demonstrates the role of the MYC/miR-150/FOXP1 axis in malignant B cells as a determinant of FL aggressiveness and its high-grade transformation.

Mummified Cells are a Common Finding in Cutaneous Hodgkin Lymphoma and Can Be Used as a Diagnostic Clue.

Specific cutaneous involvement in Hodgkin lymphoma is rare. In cutaneous lesions, the diagnosis is usually based on the recognition of diagnostic Reed-Sternberg cells and its variants. In nodal Hodgkin lymphoma, so-called mummified cells (cells with condensed cytoplasm and pyknotic eosinophilic or basophilic nuclei) are often seen. They are sometimes conspicuous and easy to recognize, thus serving as a clue to the diagnosis. Our objective was to study cases of cutaneous Hodgkin lymphoma to identify the occurrence of mummified cells. We studied 12 patients (4 women and 8 men; age range 23-80 years). In 6 patients, cutaneous and extracutaneous disease was identified almost simultaneously; in 4 patients, lymph node disease preceded cutaneous involvement; and in the remaining 2 patients, the skin lesions were the presenting sign, whereas lymph node involvement occurred later. Histopathological, immunohistochemical, and molecular-genetic studies, including rearrangements for TCR, IgH genes, and PCR for EBV, were performed. Cutaneous biopsy specimens revealed either a multinodular or diffuse infiltrate, included small lymphocytes, eosinophils, plasma cells, and macrophages, but in all cases, diagnostic Reed-Sternberg cells and its variants were identified. Mummified cells were detected in 9 cases, either as occasional scattered mummified cells often requiring a search (6 cases) or being conspicuous, grouped and therefore easily identified (3 cases). Immunohistochemically, in all 7 cases studied, mummified cells were positive for both CD30 and CD15. It is concluded that mummified cells are encountered in a majority of cases of cutaneous Hodgkin lymphoma.

The newly proposed International Endocervical Adenocarcinoma Criteria and Classification and its relevance to cervical cytology screening assessed in a prospective 2-year study of 118 cases.

BACKGROUND: It is generally acknowledged that interobserver variability for the histological diagnosis of endocervical adenocarcinoma (EA) subtypes is suboptimal. The recently proposed International Endocervical Adenocarcinoma Criteria and Classification (IECC) system is based on the presence of associated human papilloma virus (HPV) infection. It recognises HPV-associated EAs and non-HPV-associated EAs. METHODS: This prospective cytology-histology and molecular genetics-based study investigated the potential effect of IECC being applied to Papanicolaou (Pap) test with regard to the diagnostic accuracy of severe glandular lesions reported at least as adenocarcinoma in situ (AIS). RESULTS: Out of 118 liquid-based cytology Pap tests with AIS+ lesion, complete information on follow-up biopsy and HPV status was available in 51 cases. AIS and EA category correlated with histologically confirmed AIS/EA in 88.5% (23/26) and 70.5% (12/17) of cases, respectively. Interestingly, 93% (40/43) of cases diagnosed as AIS/EA were HPV positive and 7% (3/43) were HPV negative (originating in the cervix, endometrium and adnexa). CONCLUSIONS: Our findings suggest that this approach could possibly divide Pap tests containing severe glandular lesion into two groups: (a) robust diagnosis of HPV-associated EA and (b) non-HPV associated glandular lesions of heterogeneous origin, requiring further clinical preoperative diagnostic workup.

The detection of DNA methylation of tumour suppressor genes in cervical high-grade squamous intraepithelial lesion: A prospective cytological-histological correlation study of 70 cases.

BACKGROUND: DNA methylation has been suggested as one of the epigenetic changes promoting carcinogenesis. The aim of this study was to prospectively evaluate the methylation status of CADM 1, MAL and hsa-miR-124 genes in high-grade squamous intraepithelial lesion (HSIL) liquid-based cytology (LBC) samples with a histological correlation. METHODS: Seventy histologically confirmed cases of HSIL paired with prior screening LBC diagnosis of HSIL within a 3-month interval were selected. Histologically, the lesions were reviewed and assessed including: (a) number of blocks harbouring dysplastic squamous epithelium; (b) number of blocks containing glandular extension of dysplastic epithelium; and (c) the depth of glandular extension (which was assessed semi-quantitatively as graded 1-3). Human papillomavirus (HPV) subtyping was performed from residual LBC materials using the LINEAR ARRAY HPV Genotyping Test and in-house polymerase chain reaction targeting the HPV E1 gene. The detection of methylation silencing of tumour suppressor genes CADM1, MAL and hsa-miR-124 was performed by multiplex methylation-specific real-time polymerase chain reaction. RESULTS: A positive methylation status was detected in 41 cases (58.6%). The number of blocks with HSIL varied from one to 13. Glandular extension was seen in 44 cases with the number of blocks involved ranging from one to 10. The depth of HSIL glandular extension varied. CONCLUSION: The DNA methylation test allows HSIL lesions to be divided into two distinct groups of methylated HSIL in significantly older patients and unmethylated HSIL in younger patients. This study was not able to prove that methylation status in cervical HSIL correlates with the size of the lesion (measured by the number of blocks involved) or with HSIL propensity for endocervical glandular extension, nor with HPV type or multi-infection.

Supporting self-management of radiation-induced bowel and bladder dysfunction in pelvic-cancer rehabilitation: An ethnographic study.

AIMS AND OBJECTIVES: To describe and understand strategies that oncological nurses use to support self-management of radiation-induced bowel and bladder issues in pelvic-cancer rehabilitation patients. BACKGROUND: Nurse-led self-management of radiation-induced bowel and bladder issues holds the potential to support cancer survivors. DESIGN: An ethnographic approach was applied in this study, which adhered to Consolidated Criteria for Reporting Qualitative Research (COREQ) guidelines. METHODS: Data collection was conducted in Sweden between October 2015-April 2018, involving observations of nurses' daily work, formal and informal interviews, individual and group interviews, and reviews of relevant documents used in the studied practice. Furthermore, 15 supportive nurse-patient talks were observed, and an ethnographic analysis was performed. RESULTS: The analysis identified the following three categories of nursing strategies that support self-management of radiation-induced bowel and bladder issues in pelvic-cancer rehabilitation patients: encouraging self-reflection, tailoring solutions together and keeping patients motivated. Nurses and patients jointly make sense of patients' symptoms using data that patients collect about themselves. Based on their shared understanding, they can co-create solutions to meet each individual patient's needs and develop routines to keep the patient motivated in performing the devised solutions. CONCLUSIONS: The results indicate that the strategies nurses use to support patients in self-management of radiation-induced bowel and bladder issues entail intertwining patients' experiences with their nurses' medical knowledge and specific clinical practice. Nurses' strategies build on their ability to connect patients' experiences and the elements of their own work practice. RELEVANCE TO CLINICAL PRACTICE: A deeper understanding of nurses' strategies to support self-management of radiation-induced bowel and bladder issues in pelvic-cancer rehabilitation patients can improve other self-management programmes, inform nurses' education and aid in the design of tools for pelvic-cancer rehabilitation support.

Ibrutinib inhibits CD20 upregulation on CLL B cells mediated by the CXCR4/SDF-1 axis.

Agents targeting B-cell receptor (BCR) signaling-associated kinases such as Bruton tyrosine kinase (BTK) or phosphatidylinositol 3-kinase can induce mobilization of neoplastic B cells from the lymphoid tissues into the blood, which makes them potentially ideal to combine with anti-CD20 monoclonal antibodies (such as rituximab, obinutuzumab, or ofatumumab) for treatment of B-cell lymphomas and chronic lymphocytic leukemia (CLL). Here we show that interactions between leukemia cells and stromal cells (HS-5) upregulate CD20 on CLL cells and that administering ibrutinib downmodulates CD20 (MS4A1) expression in vivo. We observed that CLL cells that have recently exited the lymph node microenvironment and moved into the peripheral blood (CXCR4(dim)CD5(bright) subpopulation) have higher cell surface levels of CD20 than the cells circulating in the bloodstream for a longer time (CXCR4(bright)CD5(dim) cells). We found that CD20 is directly upregulated by CXCR4 ligand stromal cell-derived factor 1 (SDF-1α, CXCL12) produced by stromal cells, and BTK-inhibitor ibrutinib and CXCR4-inhibitor plerixafor block SDF-1α-mediated CD20 upregulation. Ibrutinib also downmodulated Mcl1 levels in CLL cells in vivo and in coculture with stromal cells. Overall, our study provides a first detailed mechanistic explanation of CD20 expression regulation in the context of chemokine signaling and microenvironmental interactions, which may have important implications for microenvironment-targeting therapies.

Results of morphological screening for Lynch syndrome during the period 2013-2016.

The introduction of a screening system for Lynch syndrome in pathology laboratories in Plzen yielded 24 diagnoses of Lynch syndrome during the period of 2013-2016, 20 of them presenting with colorectal cancer. In 8 of those 24 cases germline mutations of MMR genes, previously not recognized as pathogenic with certainty, were detected. Although the frequency of Lynch syndrome in patients with colorectal cancer was only 0.34 % in total, following introduction of the universal immunohistochemical investigation of MMR (mismatch repair) proteins expression in all colorectal cancers examined in Sikl´s Institute of Pathology the frequency per year in this department reached 2.4 %. The results favor universal immunohistochemical screening for Lynch syndrome in colorectal and endometrial cancer cases over a selective approach based on a combination of clinical and morphological criteria. Increased effectiveness of the universal approach is not brought about only by higher sensitivity of the immunohistochemical examination per se, but also by the possibility of automation of the process leading to increased adherence even of pathologists not directly engaged in Lynch syndrome management. However, the introduction of a nation-wide universal screening system requires support from the government and health insurance companies. Keywords: colorectal cancer - endometrial cancer - immunohistochemistry - Lynch syndrome - MMR - screening.

Identification of novel sequence variations in microRNAs in chronic lymphocytic leukemia.

MicroRNA (miRNA) expression is deregulated in many tumors including chronic lymphocytic leukemia (CLL). Although the particular mechanism(s) responsible for their aberrant expression is not well characterized, the presence of mutations and single-nucleotide polymorphisms (SNPs) in miRNA genes, possibly affecting their secondary structure and expression, has been described. In CLL; however, the impact and frequency of such variations have yet to be elucidated. Using a custom resequencing microarray, we screened sequence variations in 109 cancer-related pre-miRNAs in 98 CLL patients. Additionally, the primary regions of miR-29b-2/29c and miR-16-1 were analyzed by Sanger sequencing in another cohort of 213 and 193 CLL patients, respectively. Altogether, we describe six novel miR-sequence variations and the presence of SNPs (n = 27), most of which changed the miR-secondary structure. Moreover, some of the identified SNPs have a significantly different frequency in CLL when compared with a control population. Additionally, we identified a novel variation in miR-16-1 that had not been described previously in CLL patients. We show that this variation affects the expression of mature miR-16-1. We also show that the expression of another miRNA with pathogenetic relevance for CLL, namely miR-29b-2, is influenced by the presence of a polymorphic insertion, which is more frequent in CLL than in a control population. Altogether, these data suggest that sequence variations may occur during CLL development and/or progression.

MicroRNA-650 expression is influenced by immunoglobulin gene rearrangement and affects the biology of chronic lymphocytic leukemia.

MicroRNAs (miRNAs) play a key role in chronic lymphocytic leukemia as well as in normal B cells. Notably, miRNA gene encoding miR-650 and its homologs overlap with several variable (V) subgenes coding for lambda immunoglobulin (IgLλ). Recent studies describe the role of miR-650 in solid tumors, but its role in chronic lymphocytic leukemia (CLL) has not yet been studied. Our experiments demonstrate that miR-650 expression is regulated by coupled expression with its host gene for IgLλ. This coupling provides a unique yet unobserved mechanism for microRNA gene regulation. We determine that higher expression of miR-650 is associated with a favorable CLL prognosis and influences the proliferation capacity of B cells. We also establish that in B cells, miR-650 targets proteins important in cell proliferation and survival: cyclin dependent kinase 1 (CDK1), inhibitor of growth 4 (ING4), and early B-cell factor 3 (EBF3). This study underscores the importance of miR-650 in CLL biology and normal B-cell physiology.

[Lynch syndrome in the hands of pathologists]. / Lynchuv syndrom v rukách patologa.

Lynch syndrome (formerly hereditary non-polyposis colorectal cancer) is the most common familial colorectal cancer syndrome with a known molecular genetic background. The syndrome is caused by a germline mutation of one of the genes encoding mismatch repair (MMR) proteins that are responsible for DNA replication errors repair. Impaired function of these proteins leads to microsatellite instability (MSI) and forms a suitable background for the development and progression of tumors, mainly colorectal cancer. Traditionally, Lynch syndrome was regarded to be responsible for 2 % of all cases of colorectal cancer, however recent estimates reach even 5 %. Due to this relatively high frequency, familial occurence, the absence of the premorbid phenotype and the development of malignant tumors during the productive years of life, the correct diagnosis becomes not only a medical, but also a socioeconomical problem. Unfortunately, clinical means of diagnostics of Lynch syndrome (like the Amsterdam criteria and Bethesda guidelines) lack sensitivity. It was shown that predictive models based on histological signs of MSI are more sensitive than the clinical criteria used to detect patients suspicious of Lynch syndrome. Of all MSI-H colorectal cancers, 1/5 is caused by Lynch syndrome, the rest being only sporadic cancers caused by epigenetic inactivation of a MMR protein. To rule out the sporadic cases, molecular genetic investigation of the BRAF gene and methylation analysis of MLH1 is used in the diagnostic workup of Lynch syndrome. The suspicion of Lynch syndrome, based on the results of the assortment of diagnostic methods mentioned above, should be proven by detection of a germline mutation of an MMR gene in peripheral blood, and followed by screening of family members, which is a necessary condition for efficient prevention.