Biology subjects

Mine, S.

Publications and source records attributed to Mine, S..

3 recordsLinked to original sources

bioRxiv2023

Eosinophils exert direct and indirect anti-tumorigenic effects in the development of esophageal squamous cell carcinoma

Background/AimsEosinophils are present in several solid tumors and have context-dependent function. Our aim is to define the contribution of eosinophils in esophageal squamous cell carcinoma (ESCC), since their role in ESCC is unknown. MethodsEosinophils were enumerated in tissues from two ESCC cohorts. Mice were treated with 4-nitroquinolone-1-oxide (4-NQO) for 8 weeks to induce pre-cancer or 16 weeks to induce carcinoma. Eosinophil number was modified by monoclonal antibody to IL-5 (IL5mAb), recombinant IL-5 (rIL-5), or genetically with eosinophil-deficient ({Delta}dblGATA) mice or mice deficient in eosinophil chemoattractant eotaxin-1 (Ccl11-/-). Esophageal tissue and eosinophil specific RNA-sequencing was performed to understand eosinophil function. 3-D co-culturing of eosinophils with pre-cancer or cancer cells was done to ascertain direct effects of eosinophils. ResultsActivated eosinophils are present in higher numbers in early stage versus late stage ESCC. Mice treated with 4-NQO exhibit more esophageal eosinophils in pre-cancer versus cancer. Correspondingly, epithelial cell Ccl11 expression is higher in mice with pre-cancer. Eosinophil depletion using three mouse models (Ccl11-/- mice, {Delta}dblGATA mice, IL5mAb treatment) all display exacerbated 4-NQO tumorigenesis. Conversely, treatment with rIL-5 increases esophageal eosinophilia and protects against pre-cancer and carcinoma. Tissue and eosinophil RNA-sequencing revealed eosinophils drive oxidative stress in pre-cancer. In vitro co-culturing of eosinophils with pre-cancer or cancer cells resulted in increased apoptosis in the presence of a degranulating agent, which is reversed with N-acetylcysteine, a reactive oxygen species (ROS) scavenger. {Delta}dblGATA mice exhibited increased CD4 T cell infiltration, IL-17, and enrichment of IL-17 pro-tumorigenic pathways. ConclusionEosinophils likely protect against ESCC through ROS release during degranulation and suppression of IL-17.

cancer biology↗

bioRxiv2022

Characterization of SARS-CoV-2 Omicron BA.2.75 clinical isolates

The prevalence of the Omicron subvariant BA.2.75 is rapidly increasing in India and Nepal. In addition, BA.2.75 has been detected in at least 34 other countries and is spreading globally. However, the virological features of BA.2.75 are largely unknown. Here, we evaluated the replicative ability and pathogenicity of BA.2.75 clinical isolates in Syrian hamsters. Although we found no substantial differences in weight change among hamsters infected with BA.2, BA.5, or BA.2.75, the replicative ability of BA.2.75 in the lungs was higher than that of BA.2 and BA.5. Of note, BA.2.75 caused focal viral pneumonia in hamsters, characterized by patchy inflammation interspersed in alveolar regions, which was not observed in BA.5-infected hamsters. Moreover, in competition assays, BA.2.75 replicated better than BA.5 in the lungs of hamsters. These results suggest that BA.2.75 can cause more severe respiratory disease than BA.5 and BA.2 and should be closely monitored.

microbiology↗

bioRxiv2020

Suberoyl bis-hydroxamic acid reactivates Kaposis sarcoma-associated herpesvirus through histone acetylation and induces apoptosis in lymphoma cells

Kaposis sarcoma-associated herpesvirus (KSHV) is an etiologic agent of Kaposis sarcoma as well as primary effusion lymphoma (PEL), an aggressive B-cell neoplasm which mostly arises in immunocompromised individuals. At present, there is no specific treatment available for PEL and its prognosis is poor. Lytic replication of KSHV is also associated with a subset of multicentric Castleman diseases. In this study, we found that the histone deacetylase inhibitor suberoyl bis-hydroxamic acid (SBHA) induced KSHV reactivation in PEL cells in a dose-dependent manner. Next-generation sequencing analysis showed that more than 40% of all transcripts expressed in SBHA-treated PEL cells originated from the KSHV genome compared with less than 1% in untreated cells. Chromatin immunoprecipitation assays demonstrated that SBHA induced histone acetylation targeting the promoter region of the KSHV replication and transcription activator gene. However, there was no significant change in methylation status of the promoter region of this gene. In addition to its effect of KSHV reactivation, this study revealed that SBHA induces apoptosis in PEL cells in a dose-dependent manner, inducing cleavage of caspases and expression of proapoptotic factors, including Bim and Bax. These findings suggest that SBHA reactivates KSHV from latency and induces apoptosis through the mitochondrial pathway in PEL cells. Therefore, SBHA can be considered a new tool for induction of KSHV reactivation, and could provide a novel therapeutic strategy against PEL. ImportanceKaposis sarcoma and primary effusion lymphoma cells are latently infected with Kaposis sarcoma-associated herpesvirus (KSHV), whereas KSHV replication is frequently observed in multicentric Castleman disease. Although KSHV replication can be induced by some chemical reagents (e.g. 12-O-tetradecanoylphorbol-13-acetate), the mechanism of KSHV replication is not fully understood. We found that the histone deacetylase inhibitor suberoyl bis-hydroxamic acid (SBHA) induced KSHV reactivation with high efficiency, through histone acetylation in the promoter of the replication and transcription activator gene, compared with 12-O-tetradecanoylphorbol-13-acetate. SBHA also induced apoptosis through the mitochondrial pathway in KSHV-infected cells, with a lower EC50 than measured for viral reactivation. SBHA could be used in a highly efficient replication system for KSHV in vitro, and as a tool to reveal the mechanism of replication and pathogenesis of KSHV. The ability of SBHA to induce apoptosis at lower levels than needed to stimulate KSHV reactivation, indicates its therapeutic potential.

microbiology↗