This review summarizes data on microRNA (miRNA) genomic organization, biogenesis, and functions in carcinogenesis. The roles of key genes and regulatory miRNAs in molecular mechanisms and signaling ...pathways involved in the development of osteosarcoma, the most aggressive type of bone tumor striking mainly in adolescence and early adulthood, are discussed in detail. The most critical pathways in osteosarcoma pathogenesis are the Notch, Wnt, NF-κB, p53, PI3K/Akt, and MAPK pathways. The balance between cell survival and apoptosis is determined by the Wnt and NF-κB pathways, as well as by the ratio between the activities of the MAPK and PI3K/Akt pathways. Several miRNAs (miR-21, -34a, -143, -148a, -195a, -199a-3p, -382) regulate multiple target genes, pathways, and processes essential for osteosarcoma pathogenesis. Data on the key genes and regulatory miRNAs involved in metastasis and tumor cell response to drug treatment are presented. Possible applications of miRNA in osteosarcoma diagnostics and treatment are discussed.
Most current guidelines recommend two serological tests to diagnose chronic Chagas disease. When serological tests are persistently inconclusive, some guidelines recommend molecular tests. The aim of ...this investigation was to review chronic Chagas disease diagnosis literature and to summarize results of ELISA and PCR performance.
A systematic review was conducted searching remote databases (MEDLINE, LILACS, EMBASE, SCOPUS and ISIWeb) and full texts bibliography for relevant abstracts. In addition, manufacturers of commercial tests were contacted. Original investigations were eligible if they estimated sensitivity and specificity, or reliability -or if their calculation was possible - of ELISA or PCR tests, for chronic Chagas disease.
Heterogeneity was high within each test (ELISA and PCR) and threshold effect was detected only in a particular subgroup. Reference standard blinding partially explained heterogeneity in ELISA studies, and pooled sensitivity and specificity were 97.7% 96.7%-98.5% and 96.3% 94.6%-97.6% respectively. Commercial ELISA with recombinant antigens studied in phase three investigations partially explained heterogeneity, and pooled sensitivity and specificity were 99.3% 97.9%-99.9% and 97.5% 88.5%-99.5% respectively. ELISA's reliability was seldom studied but was considered acceptable. PCR heterogeneity was not explained, but a threshold effect was detected in three groups created by using guanidine and boiling the sample before DNA extraction. PCR sensitivity is likely to be between 50% and 90%, while its specificity is close to 100%. PCR reliability was never studied.
Both conventional and recombinant based ELISA give useful information, however there are commercial tests without technical reports and therefore were not included in this review. Physicians need to have access to technical reports to understand if these serological tests are similar to those included in this review and therefore correctly order and interpret test results. Currently, PCR should not be used in clinical practice for chronic Chagas disease diagnosis and there is no PCR test commercially available for this purpose. Tests limitations and directions for future research are discussed.
There are three types of metastases in ovarian cancer: lymphogenous, hematogenous, and peritoneal. Dissemination of the tumor in the peritoneum is directly related with the development of ascites and ...a poor prognosis. The purpose of this study is to determine changes in the methylation level of a group of long non-coding RNA (lncRNA) genes at different stages of ovarian cancer progression. The methylation level of 7 lncRNA genes (
LINC00472
,
LINC00886
,
MAFG-DT
,
SNHG1
,
SNHG6
,
TP53TG1
, and
TUG1
) was studied by quantitative methyl-specific PCR in 93 samples of ovarian tumors and 75 paired samples of histologically normal tissue, as well as in 29 peritoneal macroscopic metastases. Using the nonparametric Mann—Whitney test, a significant (
p
<0.001) increase in the level of methylation of the
LINC00886
,
SNHG1
,
SNHG6
, and
TUG1
genes in the tumor tissue was shown. For the
LINC00472
,
LINC00886
, and
SNHG6
genes, a significant relationship was found with the clinical stage (
p
≤0.001), as well as with the appearance of metastases for the
LINC00472
(
p
<0.001) and
SNHG6
(
p
=0.005) genes. There was a significant increase in the level of methylation of
MAFG-DT
and
TP53TG1
(
p
<0.001) genes, as well as a decrease in
LINC00886
(
p
=0.003) in peritoneal metastases relative to the primary focus. Methylation of the
LINC00472
and
SNHG6
genes can be considered as a factor in initiating ovarian cancer metastasis, and methylation of the
LINC00886
,
MAFG-DT
, and
TP53TG1
genes as a colonization factor for metastases in the peritoneum. Thus, a relationship between methylation of a group of lncRNA genes at different stages of ovarian cancer dissemination was shown, which is important for understanding the mechanisms of these processes and for developing innovative approaches to ovarian cancer therapy.
We analyzed changes in the level of methylation of CpG islands in four long non-coding RNA (lncRNA) genes
MEG3
,
ZNF667-AS1
,
GAS5
, and
SEMA3B-AS1
as promising markers of breast cancer. Methylation ...analysis was performed by quantitative methylation-specific PCR on a set of 38 paired (tumor/normal) breast cancer samples. Significantly (
p
<0.001) increased methylation was shown for three of the four lncRNA genes:
MEG3
,
ZNF667-AS1
, and
SEMA3B-AS1
. We found significant correlations of the methylation level of all the studied lncRNA genes with the stage of cancer and with lymphogenic metastasis, and for
MEG3
and
ZNF667-AS1
also with the tumor size. Methylation of
ZNF667-AS1
, and
SEMA3B-AS1
genes in breast cancer was detected for the first time. Based on these findings, new potential markers for the diagnosis and prognosis of breast cancer can be proposed.
The role of methylation of 9 miRNA genes in the pathogenesis of metastatic clear cell renal cell carcinoma was determined by quantitative methylation-specific PCR (MS-PCR). For 5 genes (
MIR125B-1
,
...MIR137
,
MIR193A
,
MIR34B/C
, and
MIR375
), a significant correlation of high methylation level with late (III-IV) stages, large size (T3+T4) of the tumor, and metastasis to lymph nodes and/or distant organs was revealed. For another group of genes (
MIR125B-1
,
MIR1258
,
MIR193A
,
MIR34B/C
, and
MIR375
), a statistically significant correlation of high methylation level with loss of differentiation in the tumor (G3-G4) was found, and the opposite pattern was found for
MIR203A
. A total of 7 microRNA genes (
MIR125B-1
,
MIR1258
,
MIR137
,
MIR193A
,
MIR203A
,
MIR34B/C
, and
MIR375
) were identified, the methylation of which is associated with the progression of metastatic clear cell renal cell carcinoma. For 6 of them (except
MIR34B/C
) these data were obtained for the first time. Thus, new factors of the development and progression of clear cell renal cell carcinoma were identified as potential biomarkers for the early diagnosis and prognosis of metastatic clear cell renal cell carcinoma.
The search for interacting long non-coding RNAs (lncRNAs), microRNAs (miRNAs), and mRNAs of protein-coding genes through the mechanism of competing endogenous RNAs in tumors of ovarian cancer ...patients was carried out. The levels of expression of 24 lncRNAs, 20 miRNAs, and 28 mRNAs of protein-coding genes involved in oncogenesis were determined by real-time PCR on a set of representative samples. Correlations between lncRNAs/miRNA and miRNA/mRNA levels in ovarian cancer samples were analyzed. We identified 8 pairs of lncRNAs/miRNA and 17 pairs of miRNA/mRNA, the expression levels of which have a negative correlation. Five triplets of potentially interacting lncRNAs/miRNA/mRNA have been identified, among which the most significant triplet is the
OIP5
-
AS1
/
miR-203a-3p
/
ZEB1
. The data obtained determine new epigenetic profiles, as well as new potential biomarkers and targets for targeted therapy of ovarian cancer patients.
Abstract
In this paper, we report an eco-friendly approach for the C(
sp
2
)–H bond selenylation of imidazopyridines and other
N
-heteroarenes as well as simple arenes at ambient temperature. This ...new protocol consists of the reaction between (
N
-hetero)-arenes and the diorganyl-diselenides and trichloroisocyanuric acid (TCCA)-ethanol reagent system. In a short reaction time, the desired selenylated products were obtained regioselectively in good yields, with tolerance for a wide range of functional groups.
Metastasis of primary tumors progresses stepwise — from change in biochemistry, morphology, and migratory patterns of tumor cells to the emergence of receptors on their surface that facilitate ...directional migration to target organs followed by the formation of a specific microenvironment in a target organ that helps attachment and survival of metastatic cells. A set of specific genes and signaling pathways mediate this process under control of microRNA. The molecular mechanisms underlying biological processes associated with tumor metastasis are reviewed in this publication using ovarian cancer, which exhibits high metastatic potential, as an example. Information and data on the genes and regulatory microRNAs involved in the formation of cancer stem cells, epithelial–mesenchymal transition, reducing focal adhesion, degradation of extracellular matrix, increasing migration activity of cancer cells, formation of spheroids, apoptosis, autophagy, angiogenesis, formation of metastases, and development of ascites are presented. Clusters of microRNAs (miR-145, miR-31, miR-506, miR-101) most essential for metastasis of ovarian cancer including the families of microRNAs (miR-200, miR-214, miR-25) with dual role, which is different in different histological types of ovarian cancer, are discussed in detail in a section of the review.
White‐sand forests are thought to host many ectomycorrhizal fungi, as demonstrated by the numerous fruiting body collections made by Rolf Singer in the lower Rio Negro in the late 1970s. Despite ...recognition of the importance of ectomycorrhizal fungi in white‐sand forests, there has not yet been a systematic examination of diversity and taxonomic composition across white‐sand forests, or more widely across lowland Amazonian forests. In an effort to broaden our view of ectomycorrhizal fungal diversity and distribution on white‐sand forests, we collected ectomycorrhizal fruiting bodies in 10 plots of white‐sand forests in Brazil and French Guiana between 2012 and 2014. We collected 221 specimens and 62 morphospecies, from the 10 plots, confirming that all studied white‐sand forests host ectomycorrhizal fungi. Additionally, we searched for taxa associated with white sands among specimens deposited in Brazilian herbaria. We report 1006 unique ectomycorrhizal specimen records in 18 Brazilian herbaria, of which 137 specimens and 64 species are reported from white‐sand forests, mainly in the state of Amazonas, Brazil. Russulaceae and Amanitaceae were frequent in all habitats, and Cortinarius were more frequent on white sands. Our results highlight the high diversity and heterogeneity of ectomycorrhizal communities on white‐sand forests, and the wide distribution of ectomycorrhizal fungi throughout Brazil, irrespective of soil type.
We studied the correlations between the levels of methylation of a group of 21 microRNA genes in 99 primary tumors and 29 macroscopic peritoneal metastases of ovarian cancer. Analysis of the level of ...methylation by quantitative methylation-specific PCR showed that co-methylation was detected for 13 pairs of microRNA genes in primary tumors and for 22 pairs in metastases. Pairs of microRNA genes that have shown significant co-methylation can be involved in common processes and pathways of gene regulation and interaction and can have common target genes. The results are highly significant and pairs of microRNA genes can be proposed as new potential markers for the diagnosis and prognosis of ovarian cancer metastasis.
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