Publications by authors named "Gryaznov S"

Telomerase and telomeres are crucial in cancer cell immortalization, making them key targets for anticancer therapies. Currently, 6-thio-dG (THIO) combined with the anti-PD-1 inhibitor Cemiplimab is under phase II clinical investigation (NCT05208944) in NSCLC patients resistant to prior immunotherapies. This study presents the design, synthesis, and evaluation of novel bimodular conjugate molecules combining telomere-targeting nucleoside analogs and phosphatidyl diglyceride groups.

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We describe here the design, synthesis, physicochemical properties, and hepatitis B antiviral activity of new 2'-O-alkyl ribonucleotide N3'→P5' phosphoramidate (2'-O-alkyl-NPO) and (thio)-phosphoramidite (2'--alkyl-NPS) oligonucleotide analogs. Oligonucleotides with different 2'-O-alkyl modifications such as 2'-O-methyl, -O-ethyl, -O-allyl, and -O-methoxyethyl combined with 3'-amino sugar-phosphate backbone were synthesized and evaluated. These molecules form stable duplexes with complementary DNA and RNA strands.

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A select group of patients with hepatocellular carcinomas (HCC) benefit from surgical, radiologic, and systemic therapies that include a combination of anti-angiogenic and immune-checkpoint inhibitors. However, because HCC is generally asymptomatic in its early stages, this not only leads to late diagnosis, but also to therapy resistance. The nucleoside analogue 6-thio-dG (THIO) is a first-in-class telomerase-mediated telomere-targeting anticancer agent.

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Article Synopsis
  • * Researchers have identified various markers to detect CSCs and circulating tumor cells (CTCs), which is essential for improving cancer diagnosis, treatment, and outcomes.
  • * New therapies, particularly immune checkpoint blockades and targeted small molecules, show potential for effectively targeting CSCs and improving cancer treatment by addressing drug resistance.
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Long noncoding RNAs (lncRNAs) can drive tumorigenesis and are susceptible to therapeutic intervention. Here, we used a large-scale CRISPR interference viability screen to interrogate cell-growth dependency to lncRNA genes in multiple myeloma (MM) and identified a prominent role for the miR-17-92 cluster host gene (MIR17HG). We show that an MIR17HG-derived lncRNA, named lnc-17-92, is the main mediator of cell-growth dependency acting in a microRNA- and DROSHA-independent manner.

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Despite the existence of a prophylactic vaccine against hepatitis B virus (HBV), chronic hepatitis B virus (CHB) infection remains the leading cause of cirrhosis and liver cancer in developing countries. Because HBV persistence is associated with insufficient host immune responses to the infection, development of an immunomodulator as a component of therapeutic vaccination may become an important strategy for treatment CHB. In the present study, we aimed to design a novel immunomodulator with the capacity to subvert immune tolerance to HBV.

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Objective: To analyze own initial experience of transoral thyroid surgery.

Material And Methods: There were 7 patients thyroid nodules who underwent surgery for the period from March 2018 to May 2019. All patients signed an informed consent to be included in the study.

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Hydrolysis of N3'-P5' phosphoramidate and thiophosphoramidate oligonucleotides with 0.1% formic acid leads to the cleavage of the 3' N-P bond and generates two products, one of which contains a 5'-phosphate. Analysis of the hydrolytic products by liquid chromatography, coupled with mass spectrometry, reveals the mass ladder from both termini, which is used to determine the sequence.

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: The development of endoscopic techniques motivated surgeons to search for alternative and more cosmetic approaches for thyroid and parathyroid surgery. Several variations of transoral access to the anterior neck areas were applied in recent years. One of them is a premandibular access proposed by Nakajo et al, it is performed through the oral vestibule by creating the working space by means of the lifting method.

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Aim: To analyze long-term own experience of NPE treatment in view of evolution of surgical sanitation of pleural cavity.

Material And Methods: The analysis included 5115 patients with NPE for the last 39 years (1977-2015). Morbidity, features of microflora of purulent exudate, changes in the structure of surgical methods were assessed.

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Aim: To present the result of transhiatal esophagectomies with simultaneous repair.

Material And Methods: The study included 67 procedures. In 35 cases surgery was carried out for adenocarcinoma of distal esophagus or cardia with high transition to esophagus, in 32 cases - for epidermal carcinoma of the esophagus.

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Aim: To develop minimally invasive and safe endoscopic access to thyroid gland.

Material And Methods: Transoral pre-mandibular video-assisted gas-free access to thyroid gland was developed in experimental study that included 19 human cadavers. Stereometric modeling defined the evaluation criteria including the form of basal arch of lower jaw and its height.

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Although telomerase is an almost universal target for cancer therapy, there has been no effective telomerase targeted inhibitor that has progressed to late stage human clinical trials. Recently, we reported that a telomerase-mediated telomere-disrupting compound, 6-thio-2'-deoxyguanosine (6-thio-dG), was very effective at targeting telomerase positive cancer cells while sparing telomerase silent normal cells. 6-thio-dG, a nucleoside analogue of the already-approved drug 6-thioguanine, is incorporated into telomeres by telomerase, resulting in disruption of the telomere-protecting shelterin complex.

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Article Synopsis
  • Glioblastoma (GBM) is a highly aggressive brain tumor often associated with high levels of telomerase activity, leading to poor patient prognosis.
  • Researchers tested the telomerase inhibitor Imetelstat in a mouse model to see how it works with radiation therapy (RT).
  • The study found that Imetelstat effectively reduced tumor size, inhibited telomerase activity, and enhanced the effectiveness of RT, suggesting it could be a valuable treatment option for GBM patients.
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Immunomodulatory nucleic acids have extraordinary promise for treating disease, yet clinical progress has been limited by a lack of tools to safely increase activity in patients. Immunomodulatory nucleic acids act by agonizing or antagonizing endosomal toll-like receptors (TLR3, TLR7/8, and TLR9), proteins involved in innate immune signaling. Immunomodulatory spherical nucleic acids (SNAs) that stimulate (immunostimulatory, IS-SNA) or regulate (immunoregulatory, IR-SNA) immunity by engaging TLRs have been designed, synthesized, and characterized.

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Aim: To reveal calcium metabolism disorders that frequently occur after thyroid surgery.

Material And Methods: The study included 202 patients who underwent thyroid surgery for different diseases and had normal calcium level in peripheral blood at baseline.

Results: Based on laboratory data postoperative hypocalcemia was diagnosed in 57 (28.

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Unlabelled: The relationships between telomerase and telomeres represent attractive targets for new anticancer agents. Here, we report that the nucleoside analogue 6-thio-2'-deoxyguanosine (6-thio-dG) is recognized by telomerase and is incorporated into de novo-synthesized telomeres. This results in modified telomeres, leading to telomere dysfunction, but only in cells expressing telomerase.

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Recent advances suggest that it may be possible to construct simple artificial cells from two subsystems: a self-replicating cell membrane and a self-replicating genetic polymer. Although multiple pathways for the growth and division of model protocell membranes have been characterized, no self-replicating genetic material is yet available. Nonenzymatic template-directed synthesis of RNA with activated ribonucleotide monomers has led to the copying of short RNA templates; however, these reactions are generally slow (taking days to weeks) and highly error prone.

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Article Synopsis
  • Imetelstat, a telomerase inhibitor, enhances the sensitivity of primary chronic lymphocytic leukemia (CLL) lymphocytes to the drug fludarabine, particularly in cases resistant to treatment.
  • The sensitization effect is linked to the basal expression of the protein Ku80, rather than telomerase activity itself.
  • The study reveals that Imetelstat disrupts the binding of Ku proteins to hTR, suggesting a potential mechanism behind fludarabine resistance in CLL lymphocytes and highlighting Imetelstat's broader effectiveness in treating this cancer.
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Homologous recombination (HR), a mechanism to accurately repair DNA in normal cells, is deregulated in cancer. Elevated/deregulated HR is implicated in genomic instability and telomere maintenance, which are critical lifelines of cancer cells. We have previously shown that HR activity is elevated and significantly contributes to genomic instability in Barrett's esophageal adenocarcinoma (BAC).

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Article Synopsis
  • Telomerase is an enzyme crucial for maintaining telomeres, often active in 90% of tumors but not in most normal cells.
  • Imetelstat sodium (GRN163L) is a new telomerase inhibitor that shows promise in preclinical trials for reducing telomerase activity in cancer cells and is currently being tested in clinical trials for lung cancer treatment.
  • GRN163L not only inhibits telomerase but also disrupts cell adhesion and alters the cytoskeleton in cancer cells, leading to halted proliferation and reduced metastasis, without relying on its telomerase activity.
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  • Telomerase is primarily active in tumor cells, making it a target for cancer therapies; this study investigates imetelstat, a telomerase inhibitor, for treating esophageal cancer.
  • Imetelstat was found to inhibit telomerase activity and reduce the colony formation ability of esophageal cancer cells within a week of treatment, while long-term use decreased cell growth based on telomere lengths.
  • Short-term imetelstat treatment caused DNA damage markers in cancer cells, suggesting it may enhance the effects of radiation therapy by increasing DNA repair foci shortly after exposure.
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Introduction: The incidence of Barrett esophageal adenocarcinoma (BEAC) has been increasing at an alarming rate in western countries. In this study, we have evaluated the therapeutic potential of sulforaphane (SFN), an antioxidant derived from broccoli, in BEAC.

Methods: BEAC cells were treated with SFN, alone or in combination with chemotherapeutic, paclitaxel, or telomerase-inhibiting agents (MST-312, GRN163L), and live cell number determined at various time points.

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Article Synopsis
  • * Modifications like 2'-OH, 2'-O-Me, and 2'-ribo-F on these nucleosides significantly enhance the stability of the resulting duplexes and allow them to form highly stable triple-stranded complexes, outpacing regular DNA in melting temperatures.
  • * The thio-phosphoramidate GRN163L (Imetelstat), a promising human telomerase inhibitor, effectively
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