The Biological Function, Mechanism, and Clinical Significance of m6A RNA Modifications in Head and Neck Carcinoma: A Systematic Review.

Head and neck squamous cell carcinoma (HNSCC) is one of the most common cancers, yet the molecular mechanisms underlying its onset and development have not yet been fully elucidated. Indeed, an in-depth understanding of the potential molecular mechanisms underlying HNSCC oncogenesis may aid the development of better treatment strategies. Recent epigenetic studies have revealed that the m6A RNA modification plays important roles in HNSCC. In this review, we summarize the role of m6A modification in various types of HNSCC, including thyroid, nasopharyngeal, hypopharyngeal squamous cell, and oral carcinoma. In addition, we discuss the regulatory roles of m6A in immune cells within the tumor microenvironment, as well as the potential molecular mechanisms. Finally, we review the development of potential targets for treating cancer based on the regulatory functions of m6A, with an aim to improving targeted therapies for HNSCC. Together, this review highlights the important roles that m6A modification plays in RNA synthesis, transport, and translation, and demonstrates that the regulation of m6A-related proteins can indirectly affect mRNA and ncRNA function, thus providing a novel strategy for reengineering intrinsic cell activity and developing simpler interventions to treat HNSCC.

Identification and biochemical characterization of a thermostable malate dehydrogenase from the mesophile Streptomyces coelicolor A3(2).

We identified and characterized a malate dehydrogenase from Streptomyces coelicolor A3(2) (ScMDH). The molecular mass of ScMDH was 73,353.5 Da with two 36,675.0 Da subunits as analyzed by matrix-assisted laser-desorption ionization-time-of-flight mass spectrometry (MALDI-TOF-MS). The detailed kinetic parameters of recombinant ScMDH are reported here. Heat inactivation studies showed that ScMDH was more thermostable than most MDHs from other organisms, except for a few extremely thermophile bacteria. Recombinant ScMDH was highly NAD(+)-specific and displayed about 400-fold (k(cat)) and 1,050-fold (k(cat)/K(m)) preferences for oxaloacetate reduction over malate oxidation. Substrate inhibition studies showed that ScMDH activity was inhibited by excess oxaloacetate (K(i)=5.8 mM) and excess L-malate (K(i)=12.8 mM). Moreover, ScMDH activity was not affected by most metal ions, but was strongly inhibited by Fe(2+) and Zn(2+). Taken together, our findings indicate that ScMDH is significantly thermostable and presents a remarkably high catalytic efficiency for malate synthesis.

[Cytokines of splenocytes in mice by different vaccination with recombinant BCG-Em14-3-3 vaccines against Echinococcus multilocularis].

OBJECTIVE: To detect the changes of cytokines of splenocytes in mice immunized by recombinant BCG-Em14-3-3 vaccines against Echinococcus multilocularis (Em). METHODS: BALB/c mice were subcutaneously and intranasally vaccinated by the BCG-Em14-3-3 vaccines respectively, with PBS as a control. The mice were challenged with Em protoscoleces eight weeks after the vaccinations. The spleens of the mice were collected 18 weeks after the infections. The splenocytes were separated and cultured with the stimulation of EmAg or ConA. The IL-2, IFN-gamma, TNF-alpha and IL-4 in the supernatants were measured with ELISA. RESULTS: Significant increase of IFN-gamma and TNF-alpha were found in the immunized mice. But the IL-4 was decreased after the vaccinations. The levels of TNF-alpha were higher in the intranasal vaccinated mice than in the subcutaneous vaccinated mice. CONCLUSIONS: TH1 response is induced in mice by rBCG-Em14-3-3 vaccines to fight against the challenge of Em protoscoleces. Intranasal vaccinations are preferable.

[Changes of cytokines of splenocytes in mice immunized by mix recombinant BCG-EmII/3 and BCG-Em14-3-3 vaccine of Em].

AIM: To investigate the changes of cytokines of splenocytes in mice immunized by mix recombinant BCG-EmII/3 and BCG-Em14-3-3 vaccine of Echinococcus multilocularis(Em) and challenged by Em protoscoleces. METHODS: BALB/c mice were vaccinated subcutaneously and intranasally by the vaccine respectively. In the eighth week of vaccination they were Challenged by Em protoscoleces.In the eighteenth week of infection they were killed for spleen. After splenocytes were separated,their culture was stimulated by EmAg or ConA and their supernatants were gathered. The levels of IL-2, IFN-gamma, TNF-alpha and IL-4 were measured by ELISA kit. Blank vector, BCG and PBS were served as control. RESULTS: In the groups of vaccine immunization, the levels of IFN-gamma and TNF-alpha increased obviously but the level of IL-4 decreased. The level of TNF-alpha in subcutaneous group was higher than that in intranasal group. CONCLUSION: Th1 response was induced in mice immunized by mix recombinant BCG-EmII/3 and BCG-Em14-3-3 vaccine of Em against the challenge by Em protoscoleces. Subcutaneous injection with this vaccine may be a good way of vaccination.

[Research progress in immunopathogenesis of cystic echinococcosis].

This article reviews the immunopathogenesis of cystic echinococcosis in the following seven aspects: innate immunity, establishment phase immunity, cystic phase immunity, influencing factor of CD4+ T cell polarization, cytokine function in infected host, Echinococcus granulosus infection and allergy, and immune evasion mechanism.

[Change of splenocyte lymphokines in mice induced by recombinant BCG-Eg95 vaccine against Echinococcus granulosus].

OBJECTIVE: To investigate the reduction of hydatid cyst weight and change of splenocyte lymphokines in mice immunized with recombinant BCG-Eg95 vaccine of Echinococcus granulosus(Eg). METHODS: BALB/C mice were subcutaneously, intranasally, orally and intramuscularly vaccinated respectively, with BCG and PBS served as controls. The mice were challenged with Eg protoscolices 8 weeks after vaccination and sacrificed in 18 weeks after infection. The weight of hydatid cyst was measured and reduction of the weight was obtained, spleens were used to separate splenocytes which were cultured under stimulation with EgAg or ConA. The supernatant was collected to measure the level of IL-2, IFN-gamma, TNF-alpha and IL-4 by ELISA. RESULTS: The hydatid cyst weight reduced by 45.77%, 18.20%, 88.05% and 92.46% respectively in the 4 immunization groups. In comparison with PBS control, the level of IL-2, IFN-gamma and TNF-alpha was (30.0+/-0) pg/ml, (65.0+/-0) pg/ml and (425.0+/-10.7) pg/ml respectively in the intramuscular group with a significant increase, but that of IL-4 decreased, with a value of (10.0+/-0) pg/ml. CONCLUSION: The recombinant BCG-Eg95 vaccination induces Thl response in mice against challenge infection.

[Osteogenic potential of fibroblasts with reconstituted telomerase activity].

OBJECTIVE: To prevent the senescence of 'seed cells' for tissue engineering, the life span of human fibroblasts is extended by reconstitution of telomerase activity, and the osteogenic potential of these fibroblasts are tested. METHODS: The pGRN145 plasmids encoding human telomerase reverse transcriptase (hTERT) were introduced into the normal human primary fibroblasts by electroporation. Telomerase activity was analyzed by TRAP-PCR assay. The beta-galactosidase stain was used to indicate the signs of cell senescence. The hTERT positive fibroblasts were then induced to form bone nodules. The bone nodules were stained by tetracycline and Alizarin Red S. RESULTS: Stable telomerase activity could be detected in the transfected fibroblasts and no signs of cell senescence were found in the fibroblasts cultured for more than 50 doublings. The hTERT positive fibroblasts could form bone nodules when they were cultured in vitro induced by bone morphogentic protein 2 and tumor necrosis factor-alpha. CONCLUSION: The fibroblasts with reconstituted telomerase activity reserve their osteogenic potential.