The Viral Janus: Viruses as Aetiological Agents and Treatment Options in Colorectal Cancer

The role of gut microbiota and drug interactions in the development of colorectal cancer

The human gut microbiota is a complex ecosystem regulating the host's environmental interaction. The same functional food or drug may have varying bioavailability and distinct effects on different individuals. Drugs such as antibiotics can alter the intestinal flora, thus affecting health. However, the relationship between intestinal flora and non-antibiotic drugs is bidirectional: it is not only affected by drugs; nevertheless, it can alter the drug structure through enzymes and change the bioavailability, biological activity, or toxicity of drugs to improve their efficacy and safety. This review summarizes the roles and mechanisms of antibiotics, antihypertensive drugs, nonsteroidal anti-inflammatory drugs, lipid-lowering drugs, hypoglycemic drugs, virus-associated therapies, metabolites, and dietary in modulating the colorectal cancer gut microbiota. It provides a reference for future antitumor therapy targeting intestinal microorganisms.

Revolutionized virome research using systems microbiology approaches

Currently, both pathogenic and commensal viruses are continuously being discovered and acknowledged as ubiquitous components of microbial communities. The advancements of systems microbiological approaches have changed the face of virome research. Here, we focus on viral metagenomic approach to study virus community and their interactions with other microbial members as well as their hosts. This review also summarizes challenges, limitations, and benefits of the current virome approaches. Potentially, the studies of virome can be further applied in various biological and clinical fields.

Colorectal Cancer Screening in Inflammatory Bowel Diseases-Can Characterization of GI Microbiome Signatures Enhance Neoplasia Detection?

Current noninvasive methods for colorectal cancer (CRC) screening are not optimized for persons with inflammatory bowel diseases (IBDs), requiring patients to undergo frequent interval screening via colonoscopy. Although colonoscopy-based screening reduces CRC incidence in IBD patients, rates of interval CRC remain relatively high, highlighting the need for more targeted approaches. In recent years, the discovery of disease-specific microbiome signatures for both IBD and CRC has begun to emerge, suggesting that stool-based biomarker detection using metagenomics and other culture-independent technologies may be useful for personalized, early, noninvasive CRC screening in IBD patients. Here we discuss the utility of the stool microbiome as a noninvasive CRC screening tool. Comparing the performance of multiple microbiome-based CRC classifiers, including several multi-cohort meta-analyses, we find that noninvasive detection of colorectal adenomas and carcinomas from microbial biomarkers is an active area of study with promising early results.

Open Reading Frame-3a gene of the 2019 novel coronavirus inhibits the occurrence and development of colorectal cancer

Intestinal microecology is composed of bacteria, fungi and viruses. As a part of intestinal microecology, viruses participate in the occurrence and development of colorectal cancer. The 2019-nCoV was detected in stool samples from patients during COVID-19, suggesting that the 2019-nCoV may be associated with intestinal microecology. However, the relationship of the 2019-nCoV and CRC is unclear. The aim of this study is to explore the role of Open Reading Frame-3a (ORF3a) of the 2019-nCoV in CRC. After the pCDH-CMV-MCS-EF1-Puro vector that provides high expression of ORF3a was transfected into the SW480 CRC cell line, immunofluorescence was used to determine the localization of ORF3a in SW480 cells. The proliferation, migration, invasion, apoptosis, and cell cycle progression of SW480 cells were measured using the Cell Counting Kit-8 (CCK-8), wound healing, Transwell assay, flow cytometry, the TUNEL assay, and propidium iodide single staining. The results showed that ORF3a inhibited the proliferation, invasion, and migration of SW480 cells and induced their apoptosis after 24, 48, 72 h. Meanwhile, ORF3a inhibited the cell cycle and blocked SW480 CRC cells in the G1 phase. In in vivo experiments, high ORF3a expression was associated with decreased tumor volume, tumor weight, relative tumor volume, and tumor activity. ORF3a inhibited the growth and induced apoptosis and necrosis of tumor tissues. Based on this, we demonstrated that ORF3a might play a role in CRC, providing a new direction for the prevention and treatment of CRC.

The Human Virome: Viral Metagenomics, Relations with Human Diseases, and Therapeutic Applications

The human body is colonized by a wide range of microorganisms. The field of viromics has expanded since the first reports on the detection of viruses via metagenomic sequencing in 2002. With the continued development of reference materials and databases, viral metagenomic approaches have been used to explore known components of the virome and discover new viruses from various types of samples. The virome has attracted substantial interest since the outbreak of the coronavirus disease 2019 (COVID-19) pandemic. Increasing numbers of studies and review articles have documented the diverse virome in various sites in the human body, as well as interactions between the human host and the virome with regard to health and disease. However, there have been few studies of direct causal relationships. Viral metagenomic analyses often lack standard references and are potentially subject to bias. Moreover, most virome-related review articles have focused on the gut virome and did not investigate the roles of the virome in other sites of the body in human disease. This review presents an overview of viral metagenomics, with updates regarding the relations between alterations in the human virome and the pathogenesis of human diseases, recent findings related to COVID-19, and therapeutic applications related to the human virome.

Interferon-induced protein 16 expression in colorectal cancer and its correlation with proliferation and immune signature markers

Interferon-induced protein 16 (IFI16) is important for innate immune recognition of foreign/damaged DNA. Abnormal IFI16 expression is closely related to the occurrence of multiple malignant tumours, but its expression pattern in colorectal cancer (CRC) remains unclear. The present study aimed to investigated IFI16 expression and association with cell proliferation in CRC tissues and adjacent normal tissues. A multiplex immunofluorescence panel of antibodies against IFI16, Ki-67 and phosphorylated (p)-ERK1/2 was applied to assess a tissue microarray (TMA). The TMA included 77 CRC samples and 74 normal adjacent tissue samples which were collected from The First People's Hospital of Yunnan Province (Kunming, China) (3 paracancerous tissues were lost because of repeated cutting). Immunohistochemistry was used to detect CD8⁺ tumour-infiltrating lymphocyte (TIL) abundance and programmed death-ligand 1 (PD-L1) expression in cancer tissues. The present study demonstrated that IFI16 localized to the nucleus of CRC cells. Although IFI16 was weakly expressed in normal mucosal epithelial cells, absent to strong expression was detectable in different patients with CRC. Typically, IFI16 was not co-localized with Ki-67 within CRC cells. The multiplex immunofluorescence data demonstrated that the proportion of IFI16^-/Ki-67⁺ cells from CRC tissues was 57.13%; however, that of IFI16⁺/Ki-67⁺ cells was 1.50%. The IFI16^-/Ki-67⁺ phenotype was significantly positively associated with the tumor-node-metastasis stage and was marginally significantly correlated with lymph node metastasis. p-ERK1/2 protein was primarily localized to the cytoplasm and cell membrane of CRC cells and sometimes to the nucleus. Although, IFI16 demonstrated a strong correlation with p-ERK1/2, IFI16 did not co-localize with p-ERK1/2 and the proportion of IFI16 and p-ERK1/2 double-negative CRC cells was 84.95%. IFI16 expression displayed no significant association with CD8⁺ TILs or PD-L1. However, a strong positive correlation between CD8⁺ TILs and PD-L1 was observed. High CD8⁺ TIL infiltration in CRC tissue was associated with lower lymph node metastasis and tumor-node-metastasis stage. In summary, the results of the present study provided a novel insight for the role of IFI16 in CRC occurrence via the regulation of cancer cell proliferation.

Acute Radiation Syndrome and the Microbiome: Impact and Review

Study of the human microbiota has been a centuries-long endeavor, but since the inception of the National Institutes of Health (NIH) Human Microbiome Project in 2007, research has greatly expanded, including the space involving radiation injury. As acute radiation syndrome (ARS) is multisystemic, the microbiome niches across all areas of the body may be affected. This review highlights advances in radiation research examining the effect of irradiation on the microbiome and its potential use as a target for medical countermeasures or biodosimetry approaches, or as a medical countermeasure itself. The authors also address animal model considerations for designing studies, and the potential to use the microbiome as a biomarker to assess radiation exposure and predict outcome. Recent research has shown that the microbiome holds enormous potential for mitigation of radiation injury, in the context of both radiotherapy and radiological/nuclear public health emergencies. Gaps still exist, but the field is moving forward with much promise.