Fucoidan MF4 from Fucus vesiculosus inhibits Lewis lung cancer via STING-TBK1-IRF3 pathway.

Fucoidan, a sulfated polysaccharide of marine origin found in brown algae and sea cucumbers, has been identified as a neuroprotective compound. In this study, a novel fucoidan MF4 was extracted from Fucus vesiculosus and isolated using Q-Sepharose fast-flow ion-exchange chromatography. The physicochemical properties of MF4 were characterized. MF4 is primarily composed of fucose, xylose, galactose, glucose, and mannose in a molar ratio of 12.3: 4.9: 1.1: 1.0: 1.1, with an average molecular weight of 67.7 kDa. Notably, MF4 demonstrated suppression of LLC tumor growth in vivo. RNA-sequencing analysis revealed that MF4 enhanced the expression of type I interferon-associated downstream genes in macrophages. Furthermore, MF4 increased the levels of phosphorylated TBK1 and IRF3 proteins in vitro. By activating the STING-TBK1-IRF3 signaling pathway, MF4 may enhance the antitumor activity of macrophages. Taken together, MF4 has promising potential as an antitumor and immunomodulatory agent.

Biomedical potency and mechanisms of marine polysaccharides and oligosaccharides: A review.

Derived from bountiful marine organisms (predominantly algae, fauna, and microorganisms), marine polysaccharides and marine oligosaccharides are intricate macromolecules that play a significant role in the growth and development of marine life. Recently, considerable attention has been paid to marine polysaccharides and marine oligosaccharides as auspicious natural products due to their promising biological attributes. Herein, we provide an overview of recent advances in the miscellaneous biological activities of marine polysaccharides and marine oligosaccharides that encompasses their anti-cancer, anti-inflammatory, antibacterial, antiviral, antioxidant, anti-diabetes mellitus, and anticoagulant properties. Furthermore, we furnish a concise summary of the underlying mechanisms governing the behavior of these biological macromolecules. We hope that this review inspires research on marine polysaccharides and marine oligosaccharides in medicinal applications while offering fresh perspectives on their broader facets.

Design and syntheses of a bimolecular STING agonist based on the covalent STING antagonist.

Cyclic GMP-AMP synthase and stimulator of interferon genes (cGAS-STING) signaling stimulators, an essential innate immunity component, monitor invading pathogen DNA and damaged self-DNA, making them an appealing target for drug development. The natural STING agonist, 2'3'-cGAMP, mounts and stabilizes the STING homodimer to trigger an antiviral or antitumor immune responses. However, cyclic-dinucleotide-based STING agonists show limited clinical effects owing to their short half-lives. To explore whether STING-dimer stabilizers could trigger STING signaling instead of cyclic dinucleotide-based molecules, we analyzed the structural characteristics of STING to design and synthesize a series of compounds based on the covalent STING inhibitor C-170, three of which were 23, 26, and 27, exhibited STING-dependent immune activation, both in vitro and in vivo. Compound 23 could act synergistically with cGAMP and other STING agonists as a promising moderate STING agonist. This indicates that promoting STING dimerization is a promising strategy for designing next-generation STING agonists.

The anti-inflammatory activity of specific-sized hyaluronic acid oligosaccharides.

Severe acute inflammatory conditions may cause tissue damage, sepsis, and death. As a critical component of the extracellular matrix, hyaluronic acid (HA) has been reported to possess pro- and anti-inflammatory properties via Toll-like receptors (TLRs). In this study, we prepared different sizes and structures of HA oligosaccharides and derivatives and investigated the effects on inflammation in vitro and in vivo. Our results showed that HA tetra-saccharide was the minimum fragment to enhance inflammation, whereas HA disaccharide competitively blocked TLR4-dependent inflammation. The enzymatic HA disaccharide (ΔHA2) inhibited lipopolysaccharide (LPS)-induced inflammation. Based on structure-activity relationship analysis, we observed that anti-inflammatory activity depended on HAs polymerization degree, acetyl group, and configuration. In addition, we demonstrated that ΔHA2 reduced LPS-induced pro-inflammatory cytokines production in vivo. ΔHA2, a native metabolite of HA polysaccharides, may have a potential role against LPS-mediated inflammatory diseases.

Sulfated polymannuroguluronate TGC161 ameliorates leukopenia by inhibiting CD4+ T cell apoptosis.

Polysaccharides have aroused considerable interest due to their diverse biological activities and low toxicity. In this study, we evaluated the effect of marine polysaccharide sulfated polymannuroguluronate (TGC161) on the leukopenia induced by chemotherapy. It is found that TGC161 ameliorates the leukopenia. Besides, TGC161 would promote CD4+ T cell differentiation and maturation in the thymus, but does not have a significant effect on precursor cells in bone marrow. Furthermore, TGC161 inhibits CD4+ T cell apoptosis in vitro. Collectively, our findings offer a natural and harmless polysaccharide to ameliorate leukopenia.

Combination of a novel microtubule inhibitor MBRI-001 and gemcitabine synergistically induces cell apoptosis by increasing DNA damage in pancreatic cancer cell lines.

Pancreatic cancer (PC) is a highly malignant cancer with poor prognosis. Although gemcitabine (GEM; 2',2'-difluoro-deoxycytidine) has been used as the first-line chemotherapeutic agent in PC treatment for decades, its limited efficacy remains a significant clinical issue, which may be resolved by GEM combination therapy. In this study, we aimed to investigate the anti-tumor effects of MBRI-001 in combination with GEM in BxPC-3 and MIA PaCa-2 human PC cell lines. In vitro and in vivo results indicate that MBRI-001 showed synergistic activity with GEM. GEM induced apoptosis by increasing DNA damage (phosphorylated core histone protein H2AX (γ-H2AX)), MBRI-001 activated mitochondrial-apoptotic pathway (cleaved poly-ADP ribose polymerase (PARP)). Thus, the combination of the two intensified both apoptosis and DNA damage and showed significantly superior anti-tumor activity compared to each agent alone. The adoption of combination of MBRI-001 with GEM may be beneficial as they act synergistically and thus, can be a potential therapeutic choice for improving the prognosis of PC patients in the future.

A genome-wide comprehensively analyses of long noncoding RNA profiling and metastasis associated lncRNAs in renal cell carcinoma.

Recently, a growing number of studies have indicated that long noncoding RNAs (lncRNAs) are emerging as new critical regulators of tumorigenesis and prognostic markers in multiple cancers. However, the expression pattern of lncRNAs and their contributions in renal cell carcinoma (RCC) remains poorly understood. In this study, we performed a genome-wide comprehensively analysis of lncRNAs profiling and clinical relevance to provide valuable lncRNA candidates for the further study in RCC. RCC and non-tumor tissues RNA sequencing data, and microarray data were obtained from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO), then, these data were annotated and analyzed to find dysregulated lncRNAs in RCC. We identified that hundreds of lncRNAs were differentially expressed in RCC tissues compared with normal tissues, and genomic variation analyses revealed that copy number amplification or deletion happened in some of these lncRNAs genome loci. Moreover, lots of lncRNAs expression levels are significantly associated RCC patients overall survival time, such as PVT1 and DUXAP8. Finally, we identified some novel metastasis associated lncRNAs in RCC (such as DUXAP8) by analyzing lncRNAs profiling in the RCC tissues from patients with metastasis compared with the primary RCC tissues without metastasis; knockdown of DUXAP8 could impair RCC cells invasive ability in vitro. Overall, our findings illuminate a lot of lncRNAs are aberrantly expressed in RCC that may offer useful resource for identification novel prognostic markers in this disease.

CD3/CD28 dynabeads induce expression of tn antigen in human t cells accompanied by hypermethylation of the cosmc promoter.

Glycosylation is an important protein post-translational modification. In this process, the intermediate product, Tn antigen, arises from somatic mutations in core1ß3-galactosyltransferase-specific molecular chaperone (Cosmc), which is required for the formation of active core1ß3-galactosyltransferase (T-synthase). As a type of tumor-associated carbohydrate antigen, Tn antigen is mainly expressed in many human tumor cells and is absent in normal cells. Surprisingly, it is also expressed in normal activated T cells after in vitro stimulation, but the mechanism underlying its expression remains unclear. This study demonstrated that Tn antigen was expressed in activated T cells and that the percentage of positive (Tn+) cells increased and subsequently decreased within 72h after stimulation with CD3/CD28 Dynabeads, with peak expression occurring at 48h. During activation, interleukin-4 (IL-4) expression in the T-cell supernatant consistently increased with Tn+ cells, and was inversely correlated with serum interferon gamma (IFN-γ) levels. Compared with unactivated (without CD3/CD28 Dynabead stimulation) T cells, the level of T-synthase transcription in activated T cells did not significantly change, whereas T-synthase activity and Cosmc transcription significantly decreased, accompanied by a further increase in methylation of the Cosmc promoter. The results also showed that Cosmc transcription and translation decreased and then increased, and that Cosmc promoter methylation was a dynamic process during T cell activation. These data suggest that hypermethylation of the Cosmc promoter may induce the expression of Tn antigen in activated T cells.

Aberrant Cosmc genes result in Tn antigen expression in human colorectal carcinoma cell line HT-29.

The Tn antigen, which arises from mutation in the Cosmc gene is one of the most common tumor associated carbohydrate antigens. Cosmc resides in X24 encoded by a single gene and functions as a specific molecular chaperone for T-synthase. While the Tn antigen cannot be detected in normal cells, Cosmc mutations inactivate T-synthase and consequently result in Tn antigen expression within certain cancers. In addition to this Cosmc mutation-induced expression, the Tn antigen is also expressed in such cell lines as Jurkat T, LSC and LS174T. Whether the Cosmc mutation is present in the colon cancer cell line HT-29 is still unclear. Here, we isolate HT-29-Tn+ cells from HT-29 cells derived from a female colon cancer patient. These HT-29-Tn+ cells show a loss of the Cosmc gene coding sequence (CDS) leading to an absence of T-synthase activity and Tn antigen expression. Additionally, almost no methylation of Cosmc CpG islands was detected in HT-29-Tn+ as well as in HT-29-Tn- and Tn- tumor cells from male patients. In contrast, the methylation frequency of CpG island of Cosmc in normal female cells was ~50%. Only one active allele of Cosmc existed in HT-29-Tn+ and HT-29-Tn- cells as based upon detection of SNP sites. These results indicate that Tn antigens expression and T-synthase inactivity in HT-29-Tn+ cells can be related to the absence of CDS in Cosmc active alleles, while an inactive allele deletion of Cosmc in HT-29 cells has no influence on Cosmc function.