Patients with metastatic melanoma are difficult to treat and have a very poor prognosis because of high resistance to therapy. Recent evidence indicates that tumors could overcome death through ...autophagy, a survival mechanism, which cancer cells use under lack of energy and nutrient deprivation. Melanoma cells have different sensitivity to temozolomide (TMZ) treatment. In this study, we showed that the combination of autophagy inhibitors chloroquine or LY294002 and TMZ induced enhanced cytotoxicity of alkylating agents on human melanoma cell lines. All assays were performed on patient-derived melanoma cell lines. The effectiveness of the combined treatment of TMZ and autophagy inhibitors was determined using an MTT assay. Next, we analyzed the expression mRNA level of Beclin 1, LC3B, and p62/STSQM1 and the relative expression of LC3B protein under combined treatment. Autophagic flux was determined by analysis of colocalization of Lysotracker Red and LC3B puncta. Apoptosis was measured by Annexin V/PI staining. Cell cycle analyses were carried out by flow cytometry. We showed that autophagy inhibition could enhance melanoma cell death combined with TMZ therapy. Chloroquine synergistically enhanced the TMZ-induced growth arrest and increased the G0/G1 population in Mel Z and Mel IL cell lines, but not Mel MTP. The expression analysis showed that autophagy involvement in TMZ enhanced cytotoxicity. Furthermore, LY294002, an early-stage autophagy, and PI3K inhibitor were found to exert similar effects. Both chloroquine and LY294002 improved the cytotoxic effect of TMZ treatment, making this combination applicable as a potent antitumor treatment for metastatic melanoma.
The survival of bacteria under antibiotic therapy varies in nature and is based on the bacterial ability to employ a wide range of fundamentally different resistance mechanisms. This great diversity ...requires a disambiguation of the term ‘resistance’ and the development of a more precise classification of bacterial survival strategies during contact with antibiotics. The absence of a unified definition for the terms ‘resistance’, ‘tolerance’ and ‘persistence’ further aggravates the imperfections of the current classification system.
This review suggests a number of original classification criteria that will take into account (1) the bacterial ability to replicate in the presence of antimicrobial agents, (2) existing evolutionary stability of a trait within a species, and (3) the presence or absence of specialized genes that determine the ability of a microorganism to decrease its own metabolism or switch it completely off.
This review describes potential advantages of the suggested classification system, which include a better understanding of the relationship between bacterial survival in the presence of antibiotics and molecular mechanisms of cellular metabolism suppression, the opportunity to pinpoint targets to identify a true bacterial resistance profile. The true resistance profile in turn, could be used to develop effective diagnostic and antimicrobial therapy methods, while taking into consideration specific bacterial survival mechanisms.
A giant congenital melanocytic nevus (GCMN) is found in 0.1% of live-born infants. If present, the lesion has a chance of about 6% to develop into malignant melanoma. Both children and adults can be ...affected by malignant melanoma arising in a giant congenital nevus. Up to 95% of GCMNs harbor NRAS mutations, and mutations in the BRAF, MC1R, TP53, and GNAQ genes have also been described. The individualization of therapy is required, but diagnostic and prognostic criteria remain controversial.
We report two cases: 1) melanoma arising in a giant congenital nevus during the first month of life complicated with neurocutaneous melanosis (NCM), and 2) melanoma arising in a giant congenital nevus during the first 6 months of life. Pathology, immunohistochemistry, and genetic analyses of tumor tissue were performed. The first case revealed only a non-pathogenic P72R polymorphism of the TP53 gene in the homozygote condition. For the second case, a Q61K mutation was detected in the NRAS gene.
Malignant melanoma associated with GCMN is rare and therefore poorly understood. Outcomes have been linked to the stage at diagnosis, but no additional pathological prognostic factors have been identified. The most frequent genetic event in giant CMNs is NRAS mutations, which was discovered in one of our cases. To accumulate evidence to improve disease prognosis and outcomes, children with congenital melanocytic nevus should be included in a systemic follow-up study from birth.
•A microarray-based method was evaluated to identify ctDNA BRAF mutations in melanoma patients.•The presence of BRAF mutations in cfDNA correlates with tumor progression (P=0.005).•Increased levels ...of cfDNA correlate with tumor progression (P=0.02).•Coincidence of genotypes between the tumor DNA and ctDNA was 65%.
Background: Circulating tumor DNA (ctDNA) holds great potential for cancer therapy and can provide diagnostic and prognostic information before and during treatment.
Methods: Plasma DNA samples from 97 melanoma patients, 20 healthy donors and 3 patients with benign skin tumors were analyzed by microarray analysis and droplet digital PCR (ddPCR).
Results: A microarray for simultaneous detection of six BRAF V600 mutations in ctDNA has been developed. The method allows the detection of 0.05% mutated DNA from WT DNA background. For paired samples (pre-surgery plasma and tumor tissue) isolated from 74 patients, the concordance of genotypes between tumor DNA and ctDNA was 65% (48/74). BRAF mutations in ctDNA were detected in 27/50 patients with BRAF-positive tumors and in 3/24 patients with BRAF wild-type tumors. The presence of ctDNA BRAF mutations in 23 plasma samples from melanoma patients undergoing therapy correlated significantly with tumor progression (P=0.005). The increase in cell-free DNA levels measured by ddPCR also correlated with disease progression (P=0.02). The concordance of results obtained by microarray identification of BRAF mutations and those obtained by ddPCR was 91%.
Conclusion: The novel microarray-based approach can be a useful non-invasive tool for accurate identification of ctDNA BRAF mutations to monitor disease progression.
Reactions between the nitrosyl iron complex with N-ethylthiourea ligands {FeSC(NH
2
)-(NHEt)
2
(NO)
2
}
+
Cl
−
•{FeSC(NH
2
)(NHEt)Cl(NO)
2
}
0
(complex
1
) and hemoglobin under aerobic and anaerobic ...conditions were studied. It was found that the protein stabilizes the complex, making it a more prolonged nitric oxide (NO) donor, namely, the rate of NO generation in the systems with oxy- and deoxyhemoglobin (determined from the kinetics of accumulation of methemoglobin and nitrosylated hemoglobin) is lower than in an aqueous buffer solution. According to EPR spectroscopy data, rotation of paramagnetic centers in the reaction mixture is hindered due to the binding of complex
1
to the protein molecule. In the system with oxyhemoglobin, the effect of oxygen on the decomposition of complex
1
was also taken into account. According to quantum chemical calculations and EPR spectroscopy data, both the cationic and neutral fragments of the title complex decompose in aqueous solution in the presence of oxygen. The decomposition pathways are proposed. The observed effects provide a prolonged action of complex
1
as a NO donor, which can increase its potential pharmacological efficacy.
Two series of novel zwitterionic water-soluble pentamethine cyanine dyes with geometrically balanced structures were synthesized and characterized. One series of cyanine dyes is the ...«zwitterionic» fluorophores, which contain positively charged trimethylammonioalkyl and negatively charged sulfonate groups. The second series of cyanine dyes contains a sulfonate group on one indolenine nucleus and a carboxyl group linked through an N-acylsulfonamide bond on the other indolenine nucleus. Dye-modified deoxyuridine triphosphates were synthesized and evaluated as reagents for nucleic acid labeling using PCR with Taq DNA-polymerase. The efficiency of the incorporation of labeled nucleotides was investigated via real-time PCR and using a «KRAS-Biochip» commercial testing system.
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•«Zwitterionic» cyanine dyes, which contain trimethylammonioalkyl and sulfonate groups were synthesized.•Electroneutral water-soluble cyanine dyes with a carboxyl group linked through an N-acylsulfonamide bond were synthesized.•The efficiency of the incorporation of dye-modified deoxyuridine triphosphates was investigated via PCR.
Background:
Mutations in homologous recombination (HR) and Fanconi anemia (FA) genes may predispose to pancreatic cancer (PC) and enable the prediction of sensitivity to platinum-based chemotherapy. ...FOLFIRINOX is a standard treatment option for non-selected PC patients and could be effective due to undiagnosed DNA repair deficiency. Here, we aimed to determine the frequency of mutations in genes involved in the HR and FA pathways, evaluate their clinical implications, and determine the objective response rate (ORR), progression-free survival (PFS), and overall survival (OS) of PC patients treated with platinum.
Methods:
We performed targeted DNA sequencing of 30 genes (ABRAXAS1, ATM, ATR, BARD1, BLM, BRCA1, BRCA2, BRIP1, CDKN2A, CHEK1, CHEK2, FANCC, FANCF, FANCG, FANCI, FANCL, FANCM, MRE11A, NBN, PALB2, PTEN, RAD50, RAD51C, RAD51D, RAD52, RAD54B, RBBP8, RINT1, SLX4, and XRCC2) for 543 PC patients.
Results:
In BRCA/PALB2-mutated patients with advanced PC (33 patients, 6.1%), the PFS and OS were higher for first-line platinum therapy than for non-platinum therapy PFS: HR = 0.28, 95% confidence interval (CI) = 0.10–0.81, p = 0.02; OS: HR = 0.31, 95% CI = 0.08–1.16, p = 0.08. Among 93 patients (17.1%) with mutations in other HR/FA genes, no statistically significant difference in PFS and OS was observed between first-line platinum therapy and non-platinum therapy (PFS: HR = 0.83, 95% CI = 0.43–1.62, p = 0.59; OS: HR = 0.58, 95% CI = 0.28–1.22, p = 0.15). For patients with early PC, no prognostic value was observed for BRCA1/2, PALB2, or other HR/FA genes mutations. Moreover, a personal history of breast, ovarian, pancreatic, or prostate cancer was identified as the only independent predictor of the risk of BRCA/PALB2 mutations (HR = 5.83, 95% CI = 2.16–15.73, p < 0.01).
Conclusion:
Mutations in the BRCA1/2 and PALB2 genes increase the sensitivity of PC to platinum agents. Thus, alterations in these genes in PC patients must be determined prior to anticancer therapy.
The polygenic risk score (PRS), together with the ɛ4 allele of the APOE gene (APOE-ɛ4), has shown high potential for Alzheimer’s disease (AD) risk prediction. The aim of this study was to validate ...the model of polygenic risk in Russian patients with dementia. A microarray-based assay was developed to identify 21 markers of polygenic risk and ɛ alleles of the APOE gene. This case–control study included 348 dementia patients and 519 cognitively normal volunteers. Cerebrospinal fluid (CSF) amyloid-β (Aβ) and tau protein levels were assessed in 57 dementia patients. PRS and APOE-ɛ4 were significant genetic risk factors for dementia. Adjusted for APOE-ɛ4, individuals with PRS corresponding to the fourth quartile had an increased risk of dementia compared to the first quartile (OR 1.85; p-value 0.002). The area under the curve (AUC) was 0.559 for the PRS model only, and the inclusion of APOE-ɛ4 improved the AUC to 0.604. PRS was positively correlated with tTau and pTau181 and inversely correlated with Aβ42/Aβ40 ratio. Carriers of APOE-ɛ4 had higher levels of tTau and pTau181 and lower levels of Aβ42 and Aβ42/Aβ40. The developed assay can be part of a strategy for assessing individuals for AD risk, with the purpose of assisting primary preventive interventions.
К ВОПРОСУ О ПОНЯТИИ ЦИФРОВОЙ ГРАМОТНОСТИ Eltsova, Olga; Emelyanova, Marina
Bulletin of the Chuvash State Pedagogical University named after I.Y. Yakovlev,
04/2020
1((106))
Journal Article
Recenzirano
В настоящей статье автором рассматривается вопрос о цифровой грамотности. Изучаются роль цифровой грамотности в современном обществе, история возникновения понятия. Приводятся ведущие определения и ...подходы к структуре понятия «цифровая грамотность». Рассмотрены основные компоненты цифровой грамотности, определена необходимость формирования цифровой грамотности на всех уровнях образования. Сделан вывод о том, что цифровая грамотность - важнейший навык, необходимый для успеха в XXI веке, наравне с умениями критически мыслить, вести коммуникацию, сотрудничать, решать проблемы.
This article addresses the issue of digital literacy; considers the role of digital literacy in modern society, the origin of the concept; provides the key definitions and approaches to the structure of digital literacy. The article also considers the main components of digital literacy, determines the need to develop digital literacy at all the levels of education; concludes that digital literacy is the most important skill for being successful in the 21st century along with the ability of critical thinking, communication, cooperation and problem solving.
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•Binimetinib combined with metformin is a promising therapy against human melanoma.•The combination of binimetinib and metformin is synergistic for melanoma cells.•The combined ...treatment provide pronounced spheroid disruption.•The combination effect correlated with increased level of AMPKα and decreased pERK.•The activity of Cyclin D1/CDK4 was reduced under combined treatment.
Melanoma is one of the most aggressive and treatment-resistant tumors that responsible for majority of skin-cancer related deaths. Here we propose a combination of MEK inhibitor binimetinib with metformin as a promising therapy against human melanoma cells in vitro, including BRAF -mutated A375, Mel Z, and Mel IL cells, and NRAS-mutated Mel MTP and Mel Me cells. Additionally, we obtained two close to clinical practice models of melanoma progression. The first one was vemurafenib-resistant Mel IL/R melanoma cells with acquired resistance to BRAF inhibition-targeted therapy, and the second one was tumor spheroids, which are 3D in vitro model of small-size solid tumors in vivo. The cytotoxicity of binimetinib and metformin was synergistic in both 2D and 3D melanoma culture and mediated through apoptotic pathway. The combination reduced the number of melanoma-formed colonies, inhibited cell invasion and migration, and led to G0/G1 cell cycle arrest through cyclin D/CDK4/CDK6 pathway. The mechanism of metformin and binimetinib synergy in melanoma cells was associated with increased activation of p-AMPKα and decreased p-ERK, but not with alterations in p-mTOR. In summary, the combination of metformin and binimetinib resulted in stronger anti-proliferative effects on melanoma cells compared to binimetinib alone, and therefore could be promising for clinical applications.
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