Unraveling the Aurora kinase A and Epstein-Barr nuclear antigen 1 axis in Epstein Barr virus associated gastric cancer

Gastric Carcinoma

Epstein-Barr virus (EBV)-associated gastric cancers (EBVaGCs) account for about 10% of gastric cancers globally, with higher prevalence in East Asia and Latin America. These cancers develop through a "gastritis-infection-cancer sequence" and are characterized by unique molecular signatures, including CpG island methylator phenotype and mutations in ARID1A and PIK3CA genes. EBVaGCs typically present in the proximal stomach with diffuse-type histology and dense lymphocytic infiltration. Key viral proteins EBNA1 and LMP2A drive oncogenesis by altering cellular processes and immune responses. The IFN-γ signature and extensive epigenetic modifications contribute to their distinct profile. Despite often presenting at advanced stages, EBVaGCs generally have a more favorable prognosis. EBV employs sophisticated strategies to evade immune detection, utilizing latent proteins and noncoding RNAs. Paradoxically, despite an immune-hot environment, EBVaGCs demonstrate effective immune evasion, partly due to the expression of immune checkpoint molecules like PD-L1 and LAG3. Treatment approaches vary based on disease stage, from endoscopic resection for early-stage cancers to systemic therapies for advanced cases. Immunotherapy, particularly PD-1/PD-L1 inhibitors, shows promising results. Emerging research suggests combining these with LAG3 inhibitors may enhance efficacy. Ongoing research and advanced genomic techniques continue to reveal new insights, paving the way for personalized therapies and novel diagnostic approaches.

Stimuli-responsive benzothiazole-phenothiazine derivatives: mechanochromism, AIE, acid sensing, and anticancer efficacy in benzo[a]pyrene-induced cancer models

Mechanofluorochromic (MFC) materials are emerging as a versatile candidate for optoelectronic and biomedical applications. In the present work, we designed and synthesized four MFC materials, namely BT-PTZ-1, BT-PTZ-2, BT-PTZO-1, and BT-PTZO-2, using Suzuki cross-coupling reaction. These materials possess benzothiazole (BT) as an acceptor moiety and different donors, including phenothiazine (PTZ) and triphenylamine (TPA), with variations in their spacer units. The photophysical properties of these derivatives have been explored, revealing solvatochromism, aggregation-induced emission (AIE), acid sensing, and mechanochromic behaviour. Single crystal X-ray analysis of BT-PTZO-2 provides crucial structural insights, revealing the twisted conformation of the TPA donor and the bent structure of the PTZ oxide spacer. The biological studies of these BT derivatives reveal the therapeutic potential against benzo[a]pyrene (B[a]P)-induced carcinogenesis in A549 (lung) and HEK293 (kidney) cells. Treatment with BT-PTZ-2 reflects anti-cancerous properties, with significant up-regulation of p53 and down-regulation of β-catenin and pNF-κB. Additionally, downregulation of mitochondrial fission protein (DRP1) and oxidative stress through DCFDA staining in lung cells are observed with BT-PTZ-2 treatment. These findings strongly suggest that BT-PTZ-2 can inhibit lung cancer cell proliferation and survival, suggesting it to be a promising anti-cancer agent. This comprehensive study of these MFC materials provides insights into their design, synthesis, and properties, in addition to their potential applications in various optoelectronic and biomedical fields.

Interplay of aurora kinase a functional residues and Epstein-barr Nuclear Antigen 1 in Epstein-barr virus associated Gastric cancer using AGS cells

Epstein-Barr virus (EBV), an oncogenic gamma-herpesvirus, belongs to group 1 carcinogen and is implicated in various cancers, including gastric cancer. Aurora Kinase A is a major mitotic protein kinase that regulates mitotic progression; overexpression and hyperactivation of AURKA commonly promote genomic instability in many tumours. However, the relationship of functional residues of AURKA and EBV in gastric cancer progression remains unknown. We reveal that AURKA overexpression and EBV infection induce aneuploidy in gastric epithelial cells. The AURKA (S89) N-terminal residue is critical for the centrosome maturation process in EBV-infected gastric epithelial cells. The kinase domain residues T287 and T288 of AURKA are essential for centrosome maturation and bipolar spindle formation in EBV-infected gastric cancer cells. We also show that AURKA 287/288 dm reduces the transcript expression of cell cycle markers involved in mitotic entry in EBV infection. This mutant also enhanced the protein expression of p53 and Rb, which was reduced in EBV infection and decreased the Survivin expression. Further, EBNA1, the latent gene of EBV, stabilises the AURKA in its wild-type form and S89A mutant but unable to stabilise in T287/288A double mutant. These mutants also induce mitotic catastrophe by regulating the apoptosis and autophagy pathway in EBV infection. AURKA287/288 dm also promotes autophagosome formation even in EBV infection. Thus, this study demonstrates that the AURKA kinase domain is essential for its functioning and progression of the oncogenesis of EBV-infected gastric epithelial cells.

The role of Helicobacter pylori in augmenting the severity of SARS-CoV-2 related gastrointestinal symptoms: An insight from molecular mechanism of co-infection

Coinfection of pathogenic bacteria and viruses is associated with multiple diseases. During the COVID-19 pandemic, the co-infection of other pathogens with SARS-CoV-2 was one of the important determinants of the severity. Although primarily a respiratory virus gastric manifestation of the SARS-CoV-2 infection was widely reported. This study highlights the possible consequences of SARS-CoV-2 -Helicobacter pylori coinfection in the gastrointestinal cells. We utilized the transfection and infection model for SARS-CoV-2 spike Delta (δ) and H. pylori respectively in colon carcinoma cell line HT-29 to develop the coinfection model to study inflammation, mitochondrial function, and cell death. The results demonstrate increased transcript levels of inflammatory markers like TLR2 (p < 0.01), IL10 (p < 0.05), TNFα (p < 0.05) and CXCL1 (p < 0.05) in pre-H. pylori infected cells as compared to the control. The protein levels of the β-Catenin (p < 0.01) and c-Myc (p < 0.01) were also significantly elevated in pre-H. pylori infected group in case of co-infection. Further investigation of apoptotic and necrotic markers (Caspase-3, Caspase-8, and RIP-1) reveals a necroptotic cell death in the coinfected cells. The infection and coinfection also damage the mitochondria in HT-29 cells, further implicating mitochondrial dysfunction in the necrotic cell death process. Our study also highlights the detrimental effect of pre-H. pylori exposure in the coinfection model compared to post-exposure and lone infection of H. pylori and SARS-CoV-2. This knowledge could aid in developing targeted interventions and therapeutic strategies to mitigate the severity of COVID-19 and improve patient outcomes.

Dataset on double mutation in PGIP of Glycine max improves defense to PG of Sclerotinia sclerotiorum

The cell wall of the Glycine max altered by the polygalacturonases (PGs) secreted by the fungus Sclerotinia sclerotiorum, causes disease and quality losses. In soybeans, a resistance protein called polygalacturonases-inhibiting proteins (PGIPs) binds to the PG to block fungal infection. The active site residues of PGIP3, VAL170 and GLN242 are mutated naturally by various amino acids in different types of PGIPs. Therefore, the mutation of VAL170 to GLY is ineffective but the GLN242 amino acid mutation by LYS significantly alters the structure and is crucial for interacting with the PG protein. Docking and Molecular Dynamics simulation provide a comprehensive evaluation of the interactions between gmPGIP and ssPG. By elucidating the structural basis of the interaction between gmPGIP and ssPG, this investigation lays a foundation for the development of targeted strategies in-order to enhance soybean resistance against Sclerotinia sclerotiorum. By leveraging this knowledge, researchers can potentially engineer soybean varieties with improved resistance to the fungus, thereby reducing disease incidence and improving crop yields.

Chromatin modifiers in human disease: from functional roles to regulatory mechanisms

The field of transcriptional regulation has revealed the vital role of chromatin modifiers in human diseases from the beginning of functional exploration to the process of participating in many types of disease regulatory mechanisms. Chromatin modifiers are a class of enzymes that can catalyze the chemical conversion of pyrimidine residues or amino acid residues, including histone modifiers, DNA methyltransferases, and chromatin remodeling complexes. Chromatin modifiers assist in the formation of transcriptional regulatory circuits between transcription factors, enhancers, and promoters by regulating chromatin accessibility and the ability of transcription factors to acquire DNA. This is achieved by recruiting associated proteins and RNA polymerases. They modify the physical contact between cis-regulatory factor elements, transcription factors, and chromatin DNA to influence transcriptional regulatory processes. Then, abnormal chromatin perturbations can impair the homeostasis of organs, tissues, and cells, leading to diseases. The review offers a comprehensive elucidation on the function and regulatory mechanism of chromatin modifiers, thereby highlighting their indispensability in the development of diseases. Furthermore, this underscores the potential of chromatin modifiers as biomarkers, which may enable early disease diagnosis. With the aid of this paper, a deeper understanding of the role of chromatin modifiers in the pathogenesis of diseases can be gained, which could help in devising effective diagnostic and therapeutic interventions.