The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) recently a global pandemic with unprecedented public health, economic and social impact. The development of effective mitigation strategies, therapeutics and vaccines relies on detailed genomic and biological characterization of the regional viruses. This study was carried out to isolate SARS-CoV-2 viruses circulating in Anatolia, and to investigate virus propagation in frequently-used cells and experimental animals. We obtained two SARS-CoV-2 viruses from nasopharngeal swabs of confirmed cases in Vero E6 cells, visualized the virions using atomic force and scanning electron microscopy and determined size distribution of the particles. Viral cytopathic effects on Vero E6 cells were initially observed at 72 h post-inoculation and reached 90% of the cells on the 5th day. The isolates displayed with similar infectivity titers, time course and infectious progeny yields. Genome sequencing revealed the viruses to be well-conserved, with less than 1% diversity compared to the prototype virus. The analysis of the viral genomes, along with the available 62 complete genomes from Anatolia, showed limited diversity (up to 0.2% on deduced amino acids) and no evidence of recombination. The most prominent sequence variation was observed on the spike protein, resulting in the substitution D614G, with a prevalence of 56.2%. The isolates produced non-fatal infection in the transgenic type I interferon knockout (IFNAR −/- ) mice, with varying neutralizing antibody titers. Hyperemia, regional consolidation and subpleural air accumulation was observed on necropsy, with similar histopathological and immunohistochemistry findings in the lungs, heart, stomach, intestines, liver, spleen and kidneys. Peak viral loads were detected in the lungs, with virus RNA present in the kidneys, jejunum, liver, spleen and heart. In conclusion, we characterized two local isolates, investigated in vitro growth dynamics in Vero E6 cells and identified IFNAR−/− mice as a potential animal model for SARS-CoV-2 experiments.

The COVID-19 (coronavirus disease-19) pandemic affected more than 180 million people around the globe, causing more than five million deaths as of January 2022. SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2), the new coronavirus, has been identified as the primary cause of the infection. The number of vaccinated people is increasing; however, prophylactic drugs are highly demanded to ensure secure social contact. A number of drug molecules have been repurposed to fight against SARS-CoV-2, and some of them have been proven to be effective in preventing hospitalization or ICU admissions. Here, we demonstrated griffithsin (GRFT), a lectin protein, to block the entry of SARS-CoV-2 and its variants, Delta and Omicron, into the Vero E6 cell lines and IFNAR –/– mouse models by attaching to the spike protein of SARS-CoV-2. Given the current mutation frequency of SARS-CoV-2, we believe that GRFT protein-based drugs will have a high impact in preventing the transmission of both the Wuhan strain as well as any other emerging variants, including Delta and Omicron variants, causing the high-speed spread of COVID-19.

Background/Aim: The challenges of cololorectal cancer (CRC) management include prediction of outcome and drug response or chemoresistance. This study aimed at examining whether βIII-tubulin (TUBB3), present in various types of normal tissues and cancer, is a biomarker for the response of colorectal neoplasms to paclitaxel. Materials and Methods: Six tissue microarrays (TMAs) including 14 colon mucosa, 78 polyps and 202 CRCs were constructed. Assessment of TUBB3 expression was performed by immunohistochemistry, and it was scored as negative, focal and positive. In the HCT116 cell line, TUBB3 expression was silenced with siRNA. Paclitaxel toxicity was evaluated in TUBB3-silenced and control HCT116 cell lines. Results: The non-neoplastic colon mucosa was negative for TUBB3, while some of colon adenomas and CRCs expressed TUBB3 in various levels from focal to diffuse. TUBB3-expressing CRCs tended to have poor prognosis and silencing of TUBB3 sensitized the cells to paclitaxel. Conclusion: TUBB3 was expressed in a subgroup of colorectal neoplasms. Suppression of TUBB3 potentialy sensitizes neoplastic cells to taxanes.Colorectal cancer (CRC) is a significant healthcare problem. Colorectal carcinogenesis is a complex process in which many molecular pathways are dysregulated. CRCs orginate from normal colon epithelium via accumulation of various genetic and epigenetic alterations (1). Effective screening can detect and eliminate precursor neoplastic lesions in the colon and rectum. In the management of advanced tumors, surgical resection is the main treatment of choice. Metastatic CRCs require treatment with adjuvant chemotherapy with or without combinations of targeted therapeutics (2). Intratumoral and intertumoral variations constitute the main challenge for effective management of these neoplasms. However, a better understanding of tumoral heterogeneity paves the way to novel strategies of patient-specific cancer treatment options (3).The eukaryotic cell cytoskeleton is composed of three cytoskeletal polymers; actin filaments, intermediate filaments, and microtubules (4). Actin-microtubule crosstalk is important for many cellular processes such as cell division, migration, axon specification and polarity (5). Microtubules (MT) are non-covalent polymers that are dynamically assembled from heterodimers of alpha and beta tubulin. Beta tubulin is a broad gene family composed of many isotypes located on different chromosomes (6, 7). Beta tubulin hydrolyzes GTP during polymerization (8). Microtubuleassociated proteins (MAPs) regulate microtubule dynamics and tubulin conformation (9). Class III β-tubulin (βIIItubulin, TUBB3) is encoded by the TUBB3 gene and is expressed in normal neural tissues, during embryogenesis and neoplastic tissues. βIII-tubulin expression is present in many neural and non-neuronal epithelial neoplasms (10,11). A monoclonal antibody detecting βIII-tubulin (TUJ1), available since 1989, presented βIII-tubulin as a neuronal marker (12).

Gastric carcinomas consist of a heterogeneous group of neoplasms with broad cytological and architectural variations. Gastric carcinomas with lymphoid stroma show poor correlation between their histomorphology and biological behavior. This contrast causes a need for more detailed analysis and molecular exploration of lymphoid stroma-rich gastric carcinomas with medullary like features and lack of glandular differentiation. In this study, we performed a detailed retrospective analysis of 53 gastric carcinomas among 654 gastric tumors from surgical resection specimens, all of which had no prominent glandular differentiation. Morphological and clinical data were compared with immunohistochemistry (MLH1, PMS2, MSH2 and MSH6 for mismatch repair mechanism deficiency; CD2, CD8 and CD163 for immune infiltration; and PD-1, PD-L1, LMP-1, ERBB2 and ki-67) besides EBER in situ hybridization and molecular studies (PCR based microsatellite instability and BRAF V600E mutation analysis). Morphological, immunohistochemical and molecular findings lead us to classify lymphoid stroma–rich advanced gastric carcinomas (n = 40/53) into two distinct entities originating from two different pathogenetic pathway: one is gastric carcinomas revealing predominantly medullary type morphology with defective DNA mismatch repair mechanism (n = 30/53) and the other is EBV associated carcinomas (n = 10/53). In addition, we suggest that biomarker based classification algorithms besides morphological evaluation are necessary to identify these two entities. Distinguishing these entities is crucial to apply different treatment strategies, including alternative treatments such as immunotherapy.