Significance of infectious agents in colorectal cancer development

An Overview of Cancer in Djibouti: Current Status, Therapeutic Approaches, and Promising Endeavors in Local Essential Oil Treatment

Djibouti, a developing economy, grapples with significant socioeconomic obstacles and the prevalence of infectious pathologies, including certain forms of neoplasms. These challenges are exacerbated by limited access to affordable medical technologies for diagnosis, coupled with a lack of preventive interventions, particularly in disadvantaged areas. The attention devoted to local phytotherapeutic treatments underscores the uniqueness of Djibouti's flora, resulting from its distinctive geographical position. International focus specifically centers on harnessing this potential as a valuable resource, emphasizing the phytoconstituents used to counter pathologies, notably carcinomas. This comprehensive overview covers a broad spectrum, commencing with an examination of the current state of knowledge, namely an in-depth investigation of oncological risk factors. Essential elements of control are subsequently studied, highlighting the fundamental prerequisites for effective management. The significance of dietary habits in cancer prevention and support is explored in depth, while traditional methods are examined, highlighting the cultural significance of indigenous essential oil therapies and encouraging further research based on the promising results.

A Narrative Literature Review on Sepsis: A Primary Manifestation of Colorectal Neoplasm

Sepsis and colorectal cancer (CRC) exhibit a complex relationship that warrants further exploration. This review delves into the interplay of factors between sepsis and CRC, uncovering shared pathophysiological traits and potential bacterial associations. Understanding these connections could pave the way for earlier diagnosis, improved management, and enhanced outcomes in CRC patients. The role of immune system dysfunction, hypoalbuminemia, and specific microbial imbalances, such as Streptococcus bovis and Clostridium septicum, are discussed. Recognizing sepsis in CRC patients is crucial for timely intervention, and tailored approaches encompassing antibiotic therapy, source control measures, and cancer treatment are essential for comprehensive care. Monitoring biomarkers and ratios can provide valuable insights into complications and overall health outcomes. A multidisciplinary approach involving various specialists is necessary to address the global burden of CRC and its association with sepsis while exploring novel interventions, such as fecal microbiota transplantation and personalized care. We conducted a thorough search using reputable databases such as PubMed, Scopus, and Google Scholar to investigate the connection between sepsis and CRC. We refined our search terms, utilized sidebar filters, and examined references in selected articles. This meticulous process helped us create a comprehensive literature review and gain valuable insights into this relationship.

Interleukin-1 alpha and high mobility group box-1 secretion in polyinosinic:polycytidylic-induced colorectal cancer cells occur via RIPK1-dependent mechanism and participate in tumourigenesis

Pathogenic infections have significant roles in the pathogenesis of colorectal cancer (CRC). These infections induce the secretion of various damage-associated molecular patterns (DAMPs) including interleukin-1 alpha (IL-1α) and high mobility group box-1 (HMGB1). Despite their implication in CRC pathogenesis, the mechanism(s) that modulate the secretion of IL-1α and HMGB1, along with their roles in promoting CRC tumourigenesis remain poorly understood. To understand the secretory mechanism, HT-29 and SW480 cells were stimulated with infectious mimetics; polyinosinic:polycytidylic acid [Poly(I:C)], lipopolysaccharide (LPS) and pro-inflammatory stimuli; tumour necrosis factor-alpha (TNF-α). IL-1α and HMGB1 secretion levels upon stimulation were determined via ELISA. Mechanism(s) mediating IL-1α and HMGB1 secretion in CRC cells were characterized using pharmacological inhibitors and CRISPR-Cas9 gene editing targeting relevant pathways. Recombinant IL-1α and HMGB1 were utilized to determine their impact in modulating pro-tumourigenic properties of CRC cells. Pharmacological inhibition showed that Poly(I:C)-induced IL-1α secretion was mediated through endoplasmic reticulum (ER) stress and RIPK1 signalling pathway. The secretion of HMGB1 was RIPK1-dependent but independent of ER stress. RIPK1-targeted CRC cell pools exhibited decreased cell viability upon Poly(I:C) stimulation, suggesting a potential role of RIPK1 in CRC cells survival. IL-1α has both growth-promoting capabilities and stimulates the production of pro-metastatic mediators, while HMGB1 only exhibits the latter; with its redox status having influence. We demonstrated a potential role of RIPK1-dependent signalling pathway in mediating the secretion of IL-1α and HMGB1 in CRC cells, which in turn enhances CRC tumorigenesis. RIPK1, IL-1α and HMGB1 may serve as potential therapeutic targets to mitigate CRC progression.

Human BKV large T genome detection in prostate cancer and benign prostatic hyperplasia tissue samples by nested PCR: A case-control study

Human BK polyomavirus (BKPyV) is a latent infectious agent in the genitourinary tract associated with hemorrhagic cystitis and nephropathy. This virus can be a risk factor for various human malignancies, including prostate cancer (PCa). It may contribute to prostate cancer development, as it demonstrates oncogenic properties by encoding oncoproteins. This study assessed the prevalence of this virus in benign and malignant prostate tissues. Between 2009 and 2019, 49 formalin-fixed paraffin-embedded (FFPE) PCa and 49 benign prostatic hyperplasia (BPH) samples were gathered from the pathology department of a tertiary care university hospital. They were used as cases and controls, respectively. After deparaffinization and DNA extraction, nested PCR was applied to identify the BKPyVgp5 gene (LTAg) using inner and outer primers. The nested PCR showed a 278-bp bond corresponding to the BKPyVgp5 genome (LTAg) in 53.1% (26/49) of PCa and 14.3% (7/49) of BPH (p<0.001). The presence of BKV was significantly associated with an increased risk of PCa development (OR=6.78, 95% CI=2.55-18.02, p<0.001). The BKV LTAg gene was significantly more prevalent in PCa samples than in BPH samples. These results demonstrate the presence of the virus in prostate cancer tissues.

Human Papillomavirus and Risk of Colorectal Cancer: An Analysis of Nationwide Claims Data

Background and Objectives: Although human papillomavirus (HPV) is a major etiology of cervical and anogenital cancers, whether it is associated with colorectal carcinogenesis is yet undetermined. Materials and Methods: The longitudinal association of HPV infection with colorectal cancer (CRC) was evaluated using 2000-2013 data from a nationwide Taiwanese claims database. In this retrospective cohort study, 358 patients with primary HPV diagnoses (HPV-infected cohort) and 1432 patients without such a diagnosis (HPV-uninfected cohort) were recruited between 2000 and 2006. Both cohorts were followed up to identify CRC incidences from 2006 to 2013. Hazard ratios (HRs) and their 95% confidence intervals (CIs) derived from Cox proportional hazards models were used to estimate the association between HPV and CRC risk. Results: The HPV-infected cohort had a significantly higher cumulative incidence of CRC than the HPV-uninfected cohort. The presence of HPV was associated with an increased risk of CRC (adjusted HR, 1.63; 95% CI, 1.02-3.62). Furthermore, the significant HPV-CRC risk association was evident in both sexes. Conclusions: This population-based cohort study reveals longitudinal evidence that HPV is associated with an increased risk of CRC. Further studies are required to verify the role of HPV in colorectal carcinogenesis.

Identification of Streptococcus gallolyticus in tumor samples of Iranian patients diagnosed with colorectal cancer

Objective

Clinical outcomes of infection by S. gallolyticus have not been investigated extensively. We aimed to determine the prevalence of S. gallolyticus in tumor specimens obtained from Iranian patients diagnosed with colorectal cancer. Polymerase chain reaction was used to confirm the presence of S. gallolyticus in patients’ tissue samples.

Results

Of 176 patients, 65 were diagnosed with colorectal cancer whereas 111 did not have any colon disease. No correlation was found between age, colonization with S. gallolyticus, gender, or risk factors. Overall, 72 (40%) patients carried S. gallolyticus; only 29% of the patients without colorectal cancer were positive for S. gallolyticus. Diagnosis of colorectal cancer and presence of S. gallolyticus significantly correlated (P = 0.006; odds ratio = 1.46; 95% CI = 1.21–3.87). Among the patients with colorectal cancer, 39 (60%) were positive with S. gallolyticus (P = 0.006) whereas 33 of 111 (29.7%) control subjects were positive for S. gallolyticus (P > 0.05); thus, 70.3% of the control subjects were not infected with S. gallolyticus. We found a high prevalence of S. gallolyticus among an Iranian cohort of patients with colorectal cancer. Despite previous reports, we report a positive correlation between colorectal cancer and S. gallolyticus colonization.

Unusually high incidence of polyomavirus JC infection in the higher grade of colorectal cancer tissues in Taiwan

Introduction

The human JC polyomavirus (JCPyV) has been detected in colorectal cancer (CRC) tissues and is suggested to contribute to CRC tumorigenesis. The rearrangement of the JCPyV regulatory region is supposedly associated with CRC development. The progression of CRC involves the stepwise accumulation of mutations. The large tumor antigen (LT) of JCPyV can trigger uncontrolled cell cycle progression by targeting oncogenes, and tumor suppressor genes, and causing chromosome instability. Few studies have focused on the presence of JCPyV DNA in the higher grade of CRC tissues.

Methods

We collected 95 tissue blocks from samples of stages I, II, III, and IV CRC. Nested PCR targeting the regulatory region of the viral genome was performed to determine the presence of JCPyV DNA in the various stages of colorectal cancer tissues.

Results

The nested PCR results showed that the positive rate of JCPyV DNA increased with the progression of CRC stages. The archetypal-like, non-rearrangement genotype of JCPyV with subtle mutations was the major genotype found in CRC samples.

Conclusions

This finding in our study suggests that there may be an association between JCPyV and CRC progression.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40001-022-00756-2.

Synthesis and Evaluation of Some New 4H-Pyran Derivatives as Antioxidant, Antibacterial and Anti-HCT-116 Cells of CRC, with Molecular Docking, Antiproliferative, Apoptotic and ADME Investigations

Colorectal cancer oncogenesis is linked to dysbiosis, oxidative stress and overexpression of CDK2. The 4H-pyran scaffold is considered an antitumoral, antibacterial and antioxidant lead as well as a CDK2 inhibitor. Herein, certain 4H-pyran derivatives were evaluated as antibacterial, antioxidant and cytotoxic agents against HCT-116 cells. Derivatives 4g and 4j inhibited all the tested Gram-positive isolates, except for B. cereus (ATCC 14579), with lower IC₅₀ values (µM) than ampicillin. In addition, 4g and 4j demonstrated the strongest DPPH scavenging and reducing potencies, with 4j being more efficient than BHT. In cell viability assays, 4d and 4k suppressed the proliferation of HCT-116 cells, with the lowest IC₅₀ values being 75.1 and 85.88 µM, respectively. The results of molecular docking simulations of 4d and 4k, inhibitory kinase assays against CDK2, along with determination of CDK2 protein concentration and the expression level of CDK2 gene in the lysates of HCT-116 treated cells, suggested that these analogues blocked the proliferation of HCT-116 cells by inhibiting kinase activity and downregulating expression levels of CDK2 protein and gene. Moreover, 4d and 4k were found to induce apoptosis in HCT-116 cells via activation of the caspase-3 gene. Lastly, compounds 4g, 4j, 4d and 4k were predicted to comply with Lipinski’s rule of five, and they are expected to possess excellent physiochemical and pharmacokinetic properties suitable for in vivo bioavailability, as predicted by the SwissADME web tool.

Antibacterial Activity of T22, a Specific Peptidic Ligand of the Tumoral Marker CXCR4

CXCR4 is a cytokine receptor used by HIV during cell attachment and infection. Overexpressed in the cancer stem cells of more than 20 human neoplasias, CXCR4 is a convenient antitumoral drug target. T22 is a polyphemusin-derived peptide and an effective CXCR4 ligand. Its highly selective CXCR4 binding can be exploited as an agent for the cell-targeted delivery and internalization of associated antitumor drugs. Sharing chemical and structural traits with antimicrobial peptides (AMPs), the capability of T22 as an antibacterial agent remains unexplored. Here, we have detected T22-associated antimicrobial activity and biofilm formation inhibition over Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa, in a spectrum broader than the reference AMP GWH1. In contrast to GWH1, T22 shows neither cytotoxicity over mammalian cells nor hemolytic activity and is active when displayed on protein-only nanoparticles through genetic fusion. Under the pushing need for novel antimicrobial agents, the discovery of T22 as an AMP is particularly appealing, not only as its mere addition to the expanding catalogue of antibacterial drugs. The recognized clinical uses of T22 might allow its combined and multivalent application in complex clinical conditions, such as colorectal cancer, that might benefit from the synchronous destruction of cancer stem cells and local bacterial biofilms.

Association of Epstein–Barr Virus and Cytomegalovirus Infections with Esophageal Carcinoma

Background: Given the fact that viral infections play an important role, either directly or indirectly, in around 20 percent of human cancers, this study aimed at investigating the potential association of Epstein–Barr virus (EBV) and cytomegalovirus (CMV) infections in esophageal cancer that is the sixth most common cause of cancer-related deaths. Methods: In this case-control study, a total of 200 paraffin-embedded biopsies of cancerous and benign esophageal tissues were gathered from the biopsy bank of Imam Reza Hospital, Tabriz, Iran in 2017. All samples were first deparaffinized, and then subjected to commercial DNA extraction. The quality of extracted DNA was evaluated by amplification of the beta globulin gene. Identification of EBV and CMV DNA was performed using primers designed for the EBER region of EBV and the immediate early (IE) region of the CMV genome, respectively. Results: The mean age of the subjects in the test and control groups was 52.2 (17.1) and 59.9 (18.9), respectively. The distribution of gender (male/female) in patient and control groups was 54/46 and 53/47, respectively. Our results showed that the frequency of EBV (P < 0.001) and CMV (P < 0.001) in cancerous samples was statistically higher than control group. Moreover, in the cancerous group the rate of EBV was significantly higher in the esophageal adenocarcinomas (EAC) sample (12 out of 70) than esophageal squamous cell carcinomas (ESCC) (0 out of 30) (P = 0.016) but, in the ESCC group, 17 out of 30 subjects were positive for CMV which was significantly higher in comparison with EAC patients (1 out of 70) (P < 0.001). Conclusions: Findings indicated that EBV and CMV might be contributed to the pathogenesis of EAC and ESCC types of esophageal carcinoma, respectively, although further studies are warranted.

Current Trends and Challenges in Pharmacoeconomic Aspects of Nanocarriers as Drug Delivery Systems for Cancer Treatment

Nanotherapy is a part of nanomedicine that involves nanoparticles as carriers to deliver drugs to target locations. This novel targeting approach has been found to resolve various problems, especially those associated with cancer treatment. In nanotherapy, the carrier plays a crucial role in handling many of the existing challenges, including drug protection before early-stage degradations of active substances, allowing them to reach targeted cells and overcome cell resistance mechanisms. The present review comprises the following sections: the first part presents the introduction of pharmacoeconomics as a branch of healthcare economics, the second part covers various beneficial aspects of the use of nanocarriers for in vitro, in vivo, and pre- and clinical studies, as well as discussion on drug resistance problem and present solutions to overcome it. In the third part, progress in drug manufacturing and optimization of the process of nanoparticle synthesis were discussed. Finally, pharmacokinetic and toxicological properties of nanoformulations due to up-to-date studies were summarized. In this review, the most recent developments in the field of nanotechnology's economic impact, particularly beneficial applications in medicine were presented. Primarily focus on cancer treatment, but also discussion on other fields of application, which are strongly associated with cancer epidemiology and treatment, was made. In addition, the current limitations of nanomedicine and its huge potential to improve and develop the health care system were presented.

Copresence of High-Risk Human Papillomaviruses and Epstein-Barr Virus in Colorectal Cancer: A Tissue Microarray and Molecular Study from Lebanon

Colorectal cancer (CRC) is the third most common cause of cancer-related deaths worldwide. Human papillomaviruses (HPVs) and Epstein-Barr virus (EBV) have been reported to be present in different types of human cancers, including CRCs, where they can play a key role in the onset and/or progression of these cancers. Thus, we herein explored the prevalence of high-risk HPVs and EBV in a cohort of 94 CRC tissue samples and 13 colorectal normal tissues from the Lebanese population using polymerase chain reaction, immunohistochemistry, and tissue microarray methodologies. We found that high-risk HPVs are present in 64%, while EBV is present in 29% of our CRC samples. Additionally, our data showed that high-risk HPV types (16, 18, 35, 58, 51, 45, 52, 31, and 33) are the most frequent in CRC in the Lebanese cohort, respectively. Our data point out that HPVs and EBV are copresent in 28% of the samples. Thus, this study clearly suggests that high-risk HPVs and EBV are present/copresent in CRCs, where they could play an important role in colorectal carcinogenesis. Nevertheless, further investigations using a larger cohort are needed to elucidate the possible cooperation between these oncoviruses in the development of CRC.

A type VII secretion system of Streptococcus gallolyticus subsp. gallolyticus contributes to gut colonization and the development of colon tumors

Streptococcus gallolyticus subspecies gallolyticus (Sgg) has a strong clinical association with colorectal cancer (CRC) and actively promotes the development of colon tumors. However, the molecular determinants involved in Sgg pathogenicity in the gut are unknown. Bacterial type VII secretion systems (T7SS) mediate pathogen interactions with their host and are important for virulence in pathogenic mycobacteria and Staphylococcus aureus. Through genome analysis, we identified a locus in Sgg strain TX20005 that encodes a putative type VII secretion system (designated as SggT7SS^T05). We showed that core genes within the SggT7SS^T05 locus are expressed in vitro and in the colon of mice. Western blot analysis showed that SggEsxA, a protein predicted to be a T7SS secretion substrate, is detected in the bacterial culture supernatant, indicating that this SggT7SS^T05 is functional. Deletion of SggT7SS^T05 (TX20005Δesx) resulted in impaired bacterial adherence to HT29 cells and abolished the ability of Sgg to stimulate HT29 cell proliferation. Analysis of bacterial culture supernatants suggest that SggT7SS^T05-secreted factors are responsible for the pro-proliferative activity of Sgg, whereas Sgg adherence to host cells requires both SggT7SS^T05-secreted and bacterial surface-associated factors. In a murine gut colonization model, TX20005Δesx showed significantly reduced colonization compared to the parent strain. Furthermore, in a mouse model of CRC, mice exposed to TX20005 had a significantly higher tumor burden compared to saline-treated mice, whereas those exposed to TX20005Δesx did not. Examination of the Sgg load in the colon in the CRC model suggests that SggT7SS^T05-mediated activities are directly involved in the promotion of colon tumors. Taken together, these results reveal SggT7SS^T05 as a previously unrecognized pathogenicity determinant for Sgg colonization of the colon and promotion of colon tumors.

Colorectal cancer (CRC) is a leading cause of cancer-related death. The development of CRC can be strongly influenced by specific gut microbes. Understanding how gut microbes modulate CRC is critical to developing novel strategies to improve clinical diagnosis and treatment of this disease. S. gallolyticus subsp. gallolyticus (Sgg) has a strong clinical association with CRC and actively promotes the development of colon tumors. However, the specific Sgg molecules that mediate its pro-tumor activity are unknown. Here we report the first characterization of a type VII secretion system (T7SS) in Sgg, designated as SggT7SS^T05. We further demonstrate that SggT7SS^T05-mediated activities are important for Sgg to colonize the colon and to promote the development of colon tumors. These findings reveal SggT7SS^T05 as a novel pathogenicity determinant of Sgg and provide a critical breakthrough in our efforts to understand how Sgg influences the development of CRC. Future investigations of the biological activities of specific effectors of SggT7SS^T05 will likely lead to the discovery of Sgg molecules that can be used as diagnostic markers and intervention targets aimed at mitigating the harmful effect of Sgg.

Microbiomes and Resistomes in Biopsy Tissue and Intestinal Lavage Fluid of Colorectal Cancer

Aim: The gut microbiome plays a crucial role in colorectal cancer (CRC) tumorigenesis, but compositions of microorganisms have been inconsistent in previous studies due to the different types of specimens. We investigated the microbiomes and resistomes of CRC patients with colonic biopsy tissue and intestinal lavage fluid (IVF). Methods: Paired samples (biopsy tissue and IVF) were collected from 20 patients with CRC, and their gut microbiomes and resistomes were measured by shotgun metagenomics. Clinical and laboratory data were recorded. Bioinformatics (KneadData, Kraken2, and FMAP) and statistical analysis were done using the R (v4.0.2) software. Results: Bacterial diversity in IVF was higher than in tissue samples, and bacterial operational taxonomic units (OTUs) were 2,757 in IVF vs. 197 in tissue. β-diversity showed distinct clusters in paired samples. The predominant bacteria in IVF were phylum Proteobacteria, while the predominant bacteria of tissue were phylum Actinobacteria. Twenty-seven representative bacteria were selected to form six bacterial clusters, which showed only Firmicutes Cluster 1, and the Bacteroidetes Cluster 1 were significantly more abundant in the IVF group than those in the tissue group (p < 0.05). The Firmicutes Cluster 2, Bacteroidetes Cluster 2, Pathogen Cluster, and Prevotella Cluster were not significantly different between IVF and tissue (p > 0.05). Correlation analysis revealed that some bacteria could have effects on metabolic and inflammatory parameters of CRC patients. A total of 1,295 antibiotic resistance genes (ARGs) were detected in the gut microbiomes, which conferred multidrug resistance, as well as resistance to tetracycline, aminoglycoside, and more. Co-occurrence patterns revealed by the network showed mainly ARG-carrying bacteria to be similar between IVF and tissue, but leading bacteria located in the hub differed between IVF and tissue. Conclusion: Heterogeneity of microbiota is particularly evident when studied with IVF and tissue samples, but bacterial clusters that have close relationships with CRC carcinogenesis are not significantly different, using IVF as an alternative to tissue for gut microbiome, and resistome assessment may be a feasible method.

Nanostructured Thin Coatings Containing Anthriscus sylvestris Extract with Dual Bioactivity

Plant extracts are highly valuable pharmaceutical complexes recognized for their biological properties, including antibacterial, antifungal, antiviral, antioxidant, anticancer, and anti-inflammatory properties. However, their use is limited by their low water solubility and physicochemical stability. In order to overcome these limitations, we aimed to develop nanostructured carriers as delivery systems for plant extracts; in particular, we selected the extract of Anthriscus sylvestris (AN) on the basis of its antimicrobial effect and antitumor activity. In this study, AN-extract-functionalized magnetite (Fe₃O₄@AN) nanoparticles (NPs) were prepared by the co-precipitation method. The purpose of this study was to synthesize and investigate the physicochemical and biological features of composite coatings based on Fe₃O₄@AN NPs obtained by matrix-assisted pulsed laser evaporation technique. In this respect, laser fluence and drop-casting studies on coatings were performed. The physical and chemical properties of laser-synthesized coatings were investigated by scanning electron microscopy, while Fourier transform infrared spectroscopy comparative analysis was used for determining the chemical structure and functional integrity. Relevant data regarding the presence of magnetic nanoparticles as the only crystalline phase and the size of nanoparticles were obtained by transmission electron microscopy. The in vitro toxicity assessment of the Fe₃O₄@AN showed significant cytotoxic activity against human adenocarcinoma HT-29 cells after prolonged exposure. Antimicrobial results demonstrated that Fe₃O₄@AN coatings inhibit microbial colonization and biofilm formation in clinically relevant bacteria species and yeasts. Such coatings are useful, natural, and multifunctional solutions for the development of tailored medical devices and surfaces.

High-Risk Human Papillomaviruses and Epstein-Barr Virus in Colorectal Cancer and Their Association with Clinicopathological Status

Colorectal cancer (CRC) is a common malignancy with a high mortality rate worldwide. It is a complex, multifactorial disease that is strongly impacted by both hereditary and environmental factors. The role of microbes (e.g., viruses) in the pathogenesis of CRC is poorly understood. In the current study, we explored the status of high-risk human papillomaviruses (HPV) and Epstein-Barr virus (EBV) in a well-defined CRC cohort using immunohistochemistry and polymerase chain reaction assays. Our data showed that high-risk HPVs were common (~80%) and EBV had a low presence (14-25%) in the CRC samples. The most common high-risk HPVs are HPV16, 31, 18, 51, 52 and 45 genotypes. The co-presence of high-risk HPV and EBV was observed in ~16% of the sample population without any significant association with the clinicopathological variables. We conclude that high-risk HPVs are very prevalent in CRC samples while EBV positivity is relatively low. The co-expression of the two viruses was observed in a minority of cases and without any correlation with the studied parameters. Further studies are necessary to confirm the clinical relevance and potential therapeutic (preventive) effects of the observations reported herein.

Multi-omic profiling reveals associations between the gut mucosal microbiome, the metabolome, and host DNA methylation associated gene expression in patients with colorectal cancer

Background

The human gut microbiome plays a critical role in the carcinogenesis of colorectal cancer (CRC). However, a comprehensive analysis of the interaction between the host and microbiome is still lacking.

Results

We found correlations between the change in abundance of microbial taxa, butyrate-related colonic metabolites, and methylation-associated host gene expression in colonic tumour mucosa tissues compared with the adjacent normal mucosa tissues. The increase of genus Fusobacterium abundance was correlated with a decrease in the level of 4-hydroxybutyric acid (4-HB) and expression of immune-related peptidase inhibitor 16 (PI16), Fc Receptor Like A (FCRLA) and Lymphocyte Specific Protein 1 (LSP1). The decrease in the abundance of another potentially 4-HB-associated genus, Prevotella 2, was also found to be correlated with the down-regulated expression of metallothionein 1 M (MT1M). Additionally, the increase of glutamic acid-related family Halomonadaceae was correlated with the decreased expression of reelin (RELN). The decreased abundance of genus Paeniclostridium and genus Enterococcus were correlated with increased lactic acid level, and were also linked to the expression change of Phospholipase C Beta 1 (PLCB1) and Immunoglobulin Superfamily Member 9 (IGSF9) respectively. Interestingly, 4-HB, glutamic acid and lactic acid are all butyrate precursors, which may modify gene expression by epigenetic regulation such as DNA methylation.

Conclusions

Our study identified associations between previously reported CRC-related microbial taxa, butyrate-related metabolites and DNA methylation-associated gene expression in tumour and normal colonic mucosa tissues from CRC patients, which uncovered a possible mechanism of the role of microbiome in the carcinogenesis of CRC. In addition, these findings offer insight into potential new biomarkers, therapeutic and/or prevention strategies for CRC.

Structure of the Mucosal and Stool Microbiome in Lynch Syndrome

The gut microbiota has been associated with colorectal cancer (CRC), but causal alterations preceding CRC have not been elucidated. To prospectively assess microbiome changes prior to colorectal neoplasia, we investigated samples from 100 Lynch syndrome patients using 16S rRNA gene sequencing of colon biopsies, coupled with metagenomic and metatranscriptomic sequencing of feces. Colectomy and CRC history represented the largest effects on microbiome profiles. A subset of Clostridiaceae were depleted in stool corresponding with baseline adenomas, while Desulfovibrio was enriched both in stool and in mucosal biopsies. A classifier leveraging stool metatranscriptomes resulted in modest power to predict interval development of preneoplastic colonic adenoma. Predictive transcripts corresponded with a shift in flagellin contributors and oxidative metabolic microenvironment, potentially factors in local CRC pathogenesis. This suggests that the effectiveness of prospective microbiome monitoring for adenomas may be limited but supports the potential causality of these consistent, early microbial changes in colonic neoplasia.

Potential Use of Biotherapeutic Bacteria to Target Colorectal Cancer-Associated Taxa

The role of the gut microbiome in human health and disease is the focus of much attention. It has been widely agreed upon that our gut bacteria play a role in host immunity, nutrient absorption, digestion, metabolism, and other key drivers of health. Furthermore, certain microbial signatures and specific taxa have also been associated with the development of diseases, such as obesity; inflammatory bowel disease; and, indeed, colorectal cancer (CRC), which is the focus of this review. By extension, such taxa represent potential therapeutic targets. In particular, the emerging human pathogen Fusobacterium nucleatum represents an important agent in CRC development and its control within the gastrointestinal tract is desirable. This paper reviews the principal bacterial pathogens that have been associated with CRC to date and discusses the in vitro and human studies that have shown the potential use of biotherapeutic strains as a means of targeting CRC-associated bacteria.

Alleviating chronic kidney disease progression through modulating the critical genus of gut microbiota in a cisplatin-induced Lanyu pig model

In the present study, we investigated the effects of Probiotic mix 1 (Pm1) with Lactobacillus plantarum subsp. plantarum, Lactobacillusparacasei subsp. paracasei, and Streptococcus salivarius subsp. thermophilus on preventing renal injury using a chronic kidney disease (CKD) minipig model previously developed in our lab using cisplatin-induced CKD in Lanyu pigs. The results indicated that the high dosage Pm1 (H.Pm1) group demonstrated lower incidence of lesions, including atrophy, mononuclear inflammation, cell infiltration, and interstitial fibrosis in renal tubules in hematoxylin and eosin (H&E) and Masson's trichrome stain. We further systematically investigated the preventing effect of Pm1. The H.Pm1 group decreased inflammatory cytokines production and increased the level of superoxide dismutase activity in plasma. The pigs fed with high dosage of Pm1 group also showed reduced both creatinine and blood urea nitrogen (BUN) when compared with the cisplatin group. Microbiota results indicated that Pm1-intervention not only reduced the abundance of Gram-negative bacteria but also affected the abundance of specific genera biomarkers, Anaerovibrio, possible_genus_SK018, Holdemanella, and Lachnospiraceae_UCG_010 in gut microbiota, leading to decreased inflammation and apoptosis in the kidney and further prevention/alleviation of the symptoms of CKD.

Identification of Quinolone and Colistin Resistance Genes in Escherichia Coli Strains Isolated from Mucosal Samples of Patients with Colorectal Cancer and Healthy Subjects

Introduction

Antibiotic resistance and extensive use of antibiotics are amongst the major causes of failure in antibiotic treatment. The purpose of this study was to investigate antibiotic resistance patterns and to identify resistance genes of quinolones and colistin in Escherichia coli. There are a very few patents on E. coli isolated from colorectal cancer. So, this study demonstrates that some bacteria resistant to ciprofloxacin have not resistance genes.Moreover, new patterns for E. coli are presented for isolates of patients with colorectal cancer.

Materials and Methods

Of the three healthy people, inflammatory bowel diseases (IBD) patients and colorectal cancer patients, 40 E. coli strains isolated after confirmation by biochemical and molecular methods. The susceptibility of isolates to antibiotics was investigated using disk diffusion test. After deoxyribonucleic acid (DNA) extraction, polymerase chain reaction (PCR) was used to identify genes encoding resistance to ciprofloxacin (qnr A, qnr B) and colistin (mcr-1).

Results

The results showed that E. coli isolates from colorectal cancer patients had the highest resistance to piperacillin (67.5%), ceftazidime (47.5%), and cefepime (42.5%). Also, E. coli strains isolated from IBD patients showed resistance to antibiotic ceftazidime 13%. More than 95% of E. coli strains isolated from healthy people were susceptible to antibiotics. Based on the results, 18 (15%) E. coli strains showed resistance to ciprofloxacin. The qnr A gene was detected in 61.11% isolates; however, qnr B was detected in 9 (50%) isolates. Isolates resistant to colistin were not observed.

Conclusion

These findings indicate increased resistance of E. coli to ciprofloxacin in comparison with prior studies. Further research in this field will increase our knowledge and more effective exposure to the antibiotic resistance of the pathogenic microorganisms.

Characterization of Mucosa-Associated Microbiota in Matched Cancer and Non-neoplastic Mucosa From Patients With Colorectal Cancer

Colonic microbiota play important roles in the development of colorectal cancer. We aim to characterise the mucosa-associated microbiota in the tumour as well as the matched non-neoplastic mucosa from patients with colorectal cancer. Microbiota profiling in these samples was done using high-throughput 16S rRNA amplicon sequencing. Our results showed that the microbiota richness and diversity were similar between the tumour and non-neoplastic mucosae. Linear discriminant analysis effect size (LEfSe) analysis identified Fusobacterium and Campylobacter as the key genera of the tumour while Brevundimonas as the key genus of the non-neoplastic mucosa. In patients with shorter survival period, the relative abundance of Fusobacterium and Campylobacter was significantly higher in the tumour. Besides, regardless of the sites, tumour showed higher abundance of Fusobacterium. On the other hand, the relative abundance of Brevundimonas was significantly lower in the tumour. When validated with quantitative ddPCR, we found the absolute numbers of both Fusobacterium and F. nucleatum were significantly higher in the carcinoma from patients with shorter survival period, conventional type of adenocarcinoma in the distal portion of the large intestine (descending colon, sigmoidal colon, and rectum). In conclusion, our study showed a compositional alteration in the mucosa-associated microbiota in the tumour, which may contribute to the progression of colorectal cancer.

The Very Low Frequency of Epstein-Barr JC and BK Viruses DNA in Colorectal Cancer Tissues in Shiraz, Southwest Iran

Viruses including Epstein-Barr virus (EBV), JCV and BKV have been reported to be associated with some cancers. The association of these viruses with colorectal cancers remains controversial. Our objective was to investigate their infections association with adenocarcinoma and adenomatous polyps of the colon. Totally, 210 paraffin-embedded tissue specimens encompassing 70 colorectal adenocarcinoma, 70 colorectal adenomatous and 70 colorectal normal tissues were included. The total DNA was extracted, then qualified samples introduced to polymerase chain reaction (PCR). The EBV, JCV and BKV genome sequences were detected using specific primers by 3 different in-house PCR assays. Out of 210 subjects, 98 cases were female and the rest were male. The mean age of the participants was 52 ± 1.64 years. EBV and JCV DNA was detected just in one (1.42%) out of seventy adenocarcinoma colorectal tissues. All adenomatous polyp and normal colorectal tissues were negative for EBV and JCV DNA sequences. Moreover, all the patients and healthy subjects were negative for BKV DNA sequences. The results suggested that EBV and JCV genomes were not detectable in the colorectal tissue of patients with colorectal cancer in our population. Hence, BKV might not be necessitated for the development of colorectal cancer. The findings merit more investigations.

Changes in the intestinal microecology induced by bacillus subtilis inhibit the occurrence of ulcerative colitis and associated cancers: a study on the mechanisms

This study aimed to explore how changes in intestinal floras caused by Bacillus subtilis (Bs) inhibited occurrence of ulcerative colitis (UC) and associated cancers. Bs was used as an intervention in an azoxymethane (AOM)/dextran sodium sulfate sodium (DSS) animal model. Stool specimens were analyzed for changes in intestinal floras. Disease activity index (DAI) scores, body mass indices, cancer counts, and other indices were calculated, while changes in the colon mucosa were observed. Compared with AOM/DSS group, carcinogenesis significantly reduced and intestinal inflammations and DAI score alleviated; diversity, evenness, and number of species of floras significantly increased; and relative abundances of Rikenellaceae and Lactobacillus increased when UC developed into cancers in the AOM/DSS + Bs group. Colon epitheliums in the mice were severely damaged in the AOM/DSS group, while mucosae were repaired in the AOM/DSS + Bs group. The mRNA expression levels of IL-6 and IL-17a were lower while those of IL-10 and TGF-β1 were higher, and the expression level of Ki-67 decreased while that of caspase 3 increased in the AOM/DSS + Bs group. Bs intervention could alter the structure of intestinal floras, repair the mucosal barrier, adjust immunity, and reduce the incidence of cancer in the AOM/DSS animal model.

Study on JV Virus in Patients with Colon Cancer Type Adenocarcinoma

Introduction:

Colorectal cancer is the most repetitious malignancies with high mortality worldwide. JC virus (JCV) is ubiquitous Polyomavirus, with seroprevalence rates ranging from 70% to 90% in adult population. Recently the role of JCV have been reported in many malignant tumors worldwide. The association of JCV was reported in patients with colon and rectum cancers. Thus this study was conducted to evaluate the association of JCV DNA in patients with colon cancer type Adenocarcinoma.

Material and Methods:

A total of 120 formalin-fixed paraffin-embedded tissue blocks samples were collected including 20/40(50%) males, 20/40(50%) females patients with Colorectal Cancer(CRC), and 80 (50% males, 50% females) patients with benign tumor as a control. DNA was extracted for all the samples. Nested PCR was carried out for detection of Vp1/T-Ag junction genome in JCV genome by Nested-PCR assay. Randomly, PCR products of 6 samples were sequenced to analysis the partial JCV DNA. The phylogeny tree was constructed to determine homology identity with other JCV.

Results:

4/40(10%) samples of test group and 10/80 (12.5%) of control samples were positive for JCV DNA (P= 0.69). Out of 4 samples positive for JC DNA, 3(7.5%) were males and 1(2.4%) female (P=0.29). The frequency of JCV DNA in age group> 50 years was 4/32(10%), while in age group <50 years was 0/8 (0%) (p= 0.29).

Conclusion:

prevalence of JCV DNA was among 10% patients with CRC and 12.5% benign tumors (p=0.69). The distribution of JCV DNA was among 7.5% male and 2.5% female (p= 0.29). The frequency of JCV DNA was among 10% cases of age group >50 years and 0% of age group <50 years (P= 0.29). The subsequent T-Ag protein expression might explain the increased risk of colorectal cancer and requires further investigation.

Emerging applications of upconverting nanoparticles in intestinal infection and colorectal cancer

Colorectal cancer is the abnormal growth of cells in colon or rectum. Recent findings have acknowledged the role of bacterial infection and chronic inflammation in colorectal cancer initiation and progression. In order to detect and treat precancerous lesions, new tools are required, which may help to prevent or identify colorectal cancer at an early stage. To date, several different screening tests are available, including endoscopy, stool-based blood tests, and radiology-based tests. However, these analyses either lack sensitivity or are of an invasive nature. The use of fluorescently labeled probes can increase the detection sensitivity. However, autofluorescence, photobleaching, and photodamage are commonly encountered problems with fluorescence imaging. Upconverting nanoparticles (UCNPs) are recently developed lanthanide-doped nanocrystals that can be used as light-triggered luminescent probes and in drug delivery systems. In this review, we comprehensively summarize the recent developments and address future prospects of UCNP-based applications for diagnostics and therapeutic approaches associated with intestinal infection and colorectal cancer.

miR-34a is a microRNA safeguard for Citrobacter-induced inflammatory colon oncogenesis

Inflammation often induces regeneration to repair the tissue damage. However, chronic inflammation can transform temporary hyperplasia into a fertile ground for tumorigenesis. Here, we demonstrate that the microRNA miR-34a acts as a central safeguard to protect the inflammatory stem cell niche and reparative regeneration. Although playing little role in regular homeostasis, miR-34a deficiency leads to colon tumorigenesis after Citrobacter rodentium infection. miR-34a targets both immune and epithelial cells to restrain inflammation-induced stem cell proliferation. miR-34a targets Interleukin six receptor (IL-6R) and Interleukin 23 receptor (IL-23R) to suppress T helper 17 (Th17) cell differentiation and expansion, targets chemokine CCL22 to hinder Th17 cell recruitment to the colon epithelium, and targets an orphan receptor Interleukin 17 receptor D (IL-17RD) to inhibit IL-17-induced stem cell proliferation. Our study highlights the importance of microRNAs in protecting the stem cell niche during inflammation despite their lack of function in regular tissue homeostasis.

Grow With the Challenge - Microbial Effects on Epithelial Proliferation, Carcinogenesis, and Cancer Therapy

The eukaryotic host is in close contact to myriads of resident and transient microbes, which influence the crucial physiological pathways. Emerging evidence points to their role of host-microbe interactions for controlling tissue homeostasis, cell fate decisions, and regenerative capacity in epithelial barrier organs including the skin, lung, and gut. In humans and mice, it has been shown that the malignant tumors of these organs harbor an altered microbiota. Mechanistic studies have shown that the altered metabolic properties and secreted factors contribute to epithelial carcinogenesis and tumor progression. Exciting recent work points toward a crucial influence of the associated microbial communities on the response to chemotherapy and immune-check point inhibitors during cancer treatment, which suggests that the modulation of the microbiota might be a powerful tool for personalized oncology. In this article, we provide an overview of how the bacterial signals and signatures may influence epithelial homeostasis across taxa from cnidarians to vertebrates and delineate mechanisms, which might be potential targets for therapy of human diseases by either harnessing barrier integrity (infection and inflammation) or restoring uncontrolled proliferation (cancer).

Bacterial diversity in the feces of dogs with CPV infection

Canine parvovirus (CPV) is a contagious disease in dogs that has high morbidity and mortality. In cases of infection, the pups tend to have a higher mortality and more severe clinical symptoms than the adult dogs because the dehydration is difficult for pups to bear. Following the natural infection, there is a rapid antibody response neutralizing the extracellular virus. As a result, virus titers in tissue and feces become markedly reduced. Hence, it is important to have an effective symptomatic therapy of supporting animals to survive in the early stages of CPV infection. Furthermore, the co-infection with bacteria could increase the severity of lesions and clinical signs as well. In this paper, we obtained the bacterial diversity in feces of CPV infected dogs with the enrichment of five bacteria genera (Shigella, Peptoclostridium, Peptostreptococcus, Streptococcus, Fusobacterium). These microorganisms may partly result in the intestinal pathology of the infection. In summary, the discussion of the bacterial biodiversity in feces of CPV infected dogs provides further insights into the pathology of CPV disease and the targets of developing more effective treatment strategies.

Variations among Streptococcus gallolyticus subsp. gallolyticus strains in connection with colorectal cancer

Streptococcus gallolyticus subsp. gallolyticus (Sg) has long been reported to display a strong association with colorectal cancer (CRC). It was recently demonstrated to actively promote the development of CRC, underscoring the importance of Sg in both clinical correlation and functional relevance in CRC. Here we investigated several clinical isolates of Sg in their interactions with human colon cancer cells and in mouse models. Some Sg strains were able to stimulate host cell proliferation (proliferation-promoting Sg, PP-Sg) whereas others were not (non-proliferation-promoting Sg, NP-Sg). PP-Sg strains adhered to colon cancer cells much better than NP-Sg strains, suggesting that close contact between Sg and host cells is important. In mice, PP-Sg is significantly better at colonizing the colon tissues of A/J mice compared to NP-Sg, however this difference was not observed in C57BL/6 mice, suggesting that Sg colonization of mouse colon tissues involves specific interactions between bacterial and host factors on the colonic epithelium. Finally, in an azoxymethane-induced mouse model of CRC, PP-Sg promoted tumor development whereas NP-Sg did not. These findings provide clues to the mechanism underlying the Sg-CRC association and have important implications to clinical studies that aim to correlate Sg with clinical and pathological features of CRC.

Streptococcus gallolyticus subsp. gallolyticus promotes colorectal tumor development

Streptococcus gallolyticus subsp. gallolyticus (Sg) has long been known to have a strong association with colorectal cancer (CRC). This knowledge has important clinical implications, and yet little is known about the role of Sg in the development of CRC. Here we demonstrate that Sg promotes human colon cancer cell proliferation in a manner that depends on cell context, bacterial growth phase and direct contact between bacteria and colon cancer cells. In addition, we observed increased level of β-catenin, c-Myc and PCNA in colon cancer cells following incubation with Sg. Knockdown or inhibition of β-catenin abolished the effect of Sg. Furthermore, mice administered with Sg had significantly more tumors, higher tumor burden and dysplasia grade, and increased cell proliferation and β-catenin staining in colonic crypts compared to mice receiving control bacteria. Finally, we showed that Sg is present in the majority of CRC patients and is preferentially associated with tumor compared to normal tissues obtained from CRC patients. These results taken together establish for the first time a tumor-promoting role of Sg that involves specific bacterial and host factors and have important clinical implications.

Review on the immunotherapy strategies against metastatic colorectal carcinoma

Colorectal cancer (CRC) is one of the most common malignancies throughout the world and the leading cause of cancer-related mortality in Western countries. Recent progress in CRC treatment options, such as surgery, chemotherapy, radiotherapy and target therapy, has improved the prognosis, but advanced disease with recurrence or distant metastasis is usually incurable and has an unfavorable prognosis. The introduction of immunotherapy-associated strategies, both active and passive, to the treatment of CRC aims to overcome the limits of classical treatments. We review the state of the art for CRC with respect to different immunotherapeutic approaches, such as the use of cancer vaccines and/or adoptive cellular therapy, their most current advances and limitations and perspectives for further improvements.

Presence of Human Papillomavirus DNA in Colorectal Cancer Tissues in Shiraz, Southwest Iran

BACKGROUND

Colorectal cancer is one of the most common cancers worldwide. Viruses including human papillomavirus (HPV) have been reported to be associated with different cancers but any association with colorectal cancers remains controversial.

AIM

To evaluate any association between HPV infection and adenocarcinoma of the colon and adenomatous polyps.

MATERIALS AND METHODS

Paraffin-embedded tissue specimens of 70 colorectal adenocarcinomas, 70 colorectal adenomatous polyps, and 70 colorectal normal tissues were subjected to DNA extraction. The quality of the extracted DNA was confirmed by amplification of a β-globin fragment using polymerase chain reaction (PCR). PCR using specific primers were performed to detect HPV DNA. Specific primers targeting the E6 region of the HPVs 16 and 18 were used for genotyping.

RESULTS

HPV DNA was detected in 2 (2.85%) out of 70 adenocarcinoma colorectal tissues and 4 (5.71%) out of 70 adenomatous colorectal tissues. All normal colorectal tissues were negative for HPV DNA. HPV-16 was the most predominant genotype (5 sample) followed by HPV-18 (4 sample). Despite the above observations, statistical analyses indicated no significant differences in the frequencies of HPV positive subjects between the cancerous and normal samples.

CONCLUSIONS

Although the differences observed in the frequencies of HPV positive cases in our study was not significant relative to those of control subjects, the fact of 6 positive samples among cancerous tissues, may still suggest a role of HPV in colorectal carcinogenesis. The study collectively indicated that some colorectal cancerous tissues are infected with high risk HPV genotype. The findings merit more investigation.

Long-term microbiota and virome in a Zürich patient after fecal transplantation against Clostridium difficile infection

Fecal microbiota transplantation (FMT) is an emerging therapeutic option for Clostridium difficile infections that are refractory to conventional treatment. FMT introduces fecal microbes into the patient's intestine that prevent the recurrence of C. difficile, leading to rapid expansion of bacteria characteristic of healthy microbiota. However, the long-term effects of FMT remain largely unknown. The C. difficile patient described in this paper revealed protracted microbiota adaptation processes from 6 to 42 months post-FMT. Ultimately, bacterial communities were donor similar, suggesting sustainable stool engraftment. Since little is known about the consequences of transmitted viruses during C. difficile infection, we also interrogated virome changes. Our approach allowed identification of about 10 phage types per sample that represented larger viral communities, and phages were found to be equally abundant in the cured patient and donor. The healthy microbiota appears to be characterized by low phage abundance. Although viruses were likely transferred, the patient established a virome distinct from the donor. Surprisingly, the patient had sequences of algal giant viruses (chloroviruses) that have not previously been reported for the human gut. Chloroviruses have not been associated with intestinal disease, but their presence in the oropharynx may influence cognitive abilities. The findings suggest that the virome is an important indicator of health or disease. A better understanding of the role of viruses in the gut ecosystem may uncover novel microbiota-modulating therapeutic strategies.

COX-2 induces lytic reactivation of EBV through PGE2 by modulating the EP receptor signaling pathway

Inflammation is one of the predisposing factors known to be associated with Epstein Barr Virus (EBV) mediated tumorigenesis. However it is not well understood whether inflammation in itself plays a role in regulating the life cycle of this infectious agent. COX-2, a key mediator of the inflammatory processes is frequently over-expressed in EBV positive cancer cells. In various tumors, PGE2 is the principle COX-2 regulated downstream product which exerts its effects on cellular processes through the EP1-4 receptors. In this study, we further elucidated how upregulated COX-2 levels can modulate the events in EBV life cycle related to latency-lytic reactivation. Our data suggest a role for upregulated COX-2 on modulation of EBV latency through its downstream effector PGE2. This study demonstrates a role for increased COX-2 levels in modulation of EBV latency. This is important for understanding the pathogenesis of EBV-associated cancers in people with chronic inflammatory conditions.

Gossypol sensitizes the antitumor activity of 5-FU through down-regulation of thymidylate synthase in human colon carcinoma cells

PURPOSE

5-Fluorouracil (5-FU) is the basic chemotherapeutic agent used to treat colon cancer. However, the sensitivity of colon cancer cells to 5-FU is limited. Gossypol is a polyphenolic extract of cottonseeds. The purpose of this study was to investigate the activities and related mechanism of gossypol alone or in combination with 5-FU against human colon carcinoma cells.

METHODS

The IC50 of gossypol or/and 5-FU in vitro was tested by 3-(4,5-dimethyl thiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay, and the drug interaction was analyzed using the CalcuSyn method. Cell apoptosis was determined using presidium iodide staining and flow cytometric analysis. Western blotting was used to determine the expression of proteins. Transient transfection method was used to silence protein.

RESULTS

The IC₅₀ at 48 h of gossypol in colon cancer cells was 26.11 ± 1.04 μmol/L in HT-29 cells, 14.11 ± 1.08 μmol/L in HCT116 cells, and 21.83 ± 1.05 μmol/L in RKO cells. When gossypol was combined with 5-FU, a synergistic cytotoxic effect was observed in HT-29 cells, HCT116 cells, and RKO cells compared with treatment with gossypol or 5-FU alone. The Western blotting results indicated that gossypol down-regulated thymidylate synthase (TS) rather than thymidine phosphorylase protein expression. Furthermore, the mTOR/p70S6K1 signaling pathway was inhibited in gossypol-treated colon cancer cells, and consequently, cyclin D1 expression was decreased, suggesting an additional mechanism of the observed antiproliferative synergistic interactions. All the observation was confirmed by silencing TS and inactivating the mTOR/p70S6K1 signaling pathway by rapamycin, both of which increased the chemo-sensitizing efficacy of 5-FU.

CONCLUSIONS

These findings suggest that gossypol-mediated down-regulation of TS, cyclin D1, and the mTOR/p70S6K1 signaling pathways enhances the anti-tumor effect of 5-FU. Ultimately, our data exposed a new action for gossypol as an enhancer of 5-FU-induced cell growth suppression.

Clinical investigation of TROP-2 as an independent biomarker and potential therapeutic target in colon cancer

Colon cancer is associated with a severe demographic and economic burden worldwide. The pathogenesis of colon cancer is highly complex and involves sequential genetic and epigenetic mechanisms. Despite extensive investigation, the pathogenesis of colon cancer remains to be elucidated. As the third most common type of cancer worldwide, the treatment options for colon cancer are currently limited. Human trophoblast cell‑surface marker (TROP‑2), is a cell‑surface transmembrane glycoprotein overexpressed by several types of epithelial carcinoma. In addition, TROP‑2 has been demonstrated to be associated with tumorigenesis and invasiveness in solid types of tumor. The aim of the present study was to investigate the protein expression of TROP‑2 in colon cancer tissues, and further explore the association between the expression of TROP‑2 and clinicopathological features of patients with colon cancer. The expression and localization of the TROP‑2 protein was examined using western blot analysis and immunofluorescence staining. Finally, the expression of TROP‑2 expression was correlated to conventional clinicopathological features of colon cancer using a χ2 test. The results revealed that TROP‑2 protein was expressed at high levels in the colon cancer tissues, which was associated with the development and pathological process of colon cancer. Therefore, TROP‑2 may be used as a biomarker to determine the clinical prognosis, and as a potential therapeutic target in colon cancer.

Potential role of Escherichia coli DNA mismatch repair proteins in colon cancer

The epithelium of gastrointestinal tract organizes many innate defense systems against microbial intruders such as integrity of epithelial, rapid eviction of infected cells, quick turnover of epithelial cell, intrinsic immune responses and autophagy. However, Enteropathogenic Escherichia coli (EPEC) are equipped with well developed infectious tricks that evade the host defense systems and utilize the gastrointestinal epithelium as a multiplicative foothold. During multiplication on and within the epithelium, EPEC secrete various toxins that can weaken, usurp, and use many host cellular systems. However, the possible mechanisms of pathogenesis are still poorly elusive. Recent study reveals the existence of EPEC in colorectal cancer patients and their potential role in depletion of DNA mismatch repair (MMR) proteins of host cell in colonic cell lines. The EPEC colonised intracellularly in colon mucosa of colorectal carcinoma whereas extracellular strain was detected in mucosa of normal colon cells. Interestingly, alteration in MutS, MutL complexes and MUTYH of mammalian cells may be involved in development of CRC. These data propose that MMR of E. coli may be potential therapeutic targets and early detection biomarkers for CRC. This article reviews the potential role of E. coli MutS, MutL and MutY protein in CRC aetiology.

Protective Effects of Turbinaria ornata and Padina pavonia against Azoxymethane-Induced Colon Carcinogenesis through Modulation of PPAR Gamma, NF-κB and Oxidative Stress

The aim of this study was to investigate the antiproliferative and protective effects of the brown seaweeds, Turbinaria ornata and Padina pavonia, against azoxymethane (AOM)-induced colon carcinogenesis in mice. Both algal extracts showed anti-proliferative effects on the human carcinoma cell line HCT-116 in vitro, with T. ornata demonstrating a more potent effect. Male albino Swiss mice received intraperitoneal injections of AOM (10 mg/kg) once a week for two consecutive weeks and 100 mg/kg of either T. ornata or P. pavonia extracts. AOM-induced mice exhibited alterations in the histological structure of the colon, elevated lipid peroxidation and nitric oxide, declined glutathione content and reduced activity of superoxide dismutase and glutathione peroxidase. In addition, AOM induced downregulation of peroxisome proliferator activated receptor gamma (PPARγ) and p53 mRNA expression, with concomitant upregulation of nuclear factor-kappa B (NF-κB) in colon tissue. Administration of either algal extract markedly alleviated the recorded alterations. In conclusion, the current study suggests that T. ornata and P. pavonia, through their antioxidant and anti-inflammatory effects, are able to attenuate colon inflammation by downregulating NF-κB expression. Furthermore, the protective effects of both algae against AOM-initiated carcinogenesis were attributed, at least in part, to their ability to upregulate colonic PPARγ and p53 expression.

Human papillomavirus infection correlates with inflammatory Stat3 signaling activity and IL-17 level in patients with colorectal cancer

Background

Colorectal cancer (CRC) is a major burden of public health and healthcare worldwide. Microbiota has been suggested in promoting chronic inflammation in the intestine which, in turn, promotes tumor development. This study focuses on possible correlations of human papillomavirus (HPV) infection with proinflammatory Stat3 signaling activities and the resulting levels of its downstream proinflammatory cytokine IL-17 in CRC patients.

Methods

HPV was examined using HPV Genotyping Chip technology and constitutively active Stat3 (p-Stat3) and IL-17 levels were tested using immunohistochemistry (IHC) in paraffin-embedded cancerous and adjacent normal tissues (ANT) from a cohort of 95 CRC patients. Correlation analyses were performed between HPV infection and clinicopathological characteristics, Stat3 activities and IL-17 levels among these CRC patients.

Results

Three major findings were observed: (1) HPV infection existed in a high rate of CRC cases (48.4%, 46/95), of which 45 cases (45/46, 97.8%) were high-risk HPV16-positive and only one case was HPV53-positive. (2) HPV infection correlated with poorer clinical stages (III+IV) of CRC. (3) HPV infection strongly correlated with both constitutively higher Stat3 activities (P<0.01) and higher IL-17 levels (P<0.01) only in CRC tissues but not in ANT tissues.

Conclusions

HPV infection is common in CRC patients suggesting potentially preventive effectiveness of HPV vaccination among high-risk young individuals. We have for the first time revealed a tri-lateral relationship among HPV infection, constitutive Stat3 activity and IL-17 level, whose collaborative act may orchestrate a proinflammatory microenvironment in the colorectum that, in turn, may promote carcinogenesis and possibly facilitate progression of CRC.

Human cytomegalovirus and Epstein-Barr virus infection impact on (18)F-FDG PET/CT SUVmax, CT volumetric and KRAS-based parameters of patients with locally advanced rectal cancer treated with neoadjuvant therapy

PURPOSE

It has long been debated whether human cytomegalovirus (HCMV) and Epstein-Barr virus (EBV) are associated with rectal cancer. The gene products of HCMV and EBV contribute to cell-cycle progression, mutagenesis, angiogenesis and immune evasion. The aim of this prospective study was to analyse the association between infection of a tumour by HCMV and EBV and clinical, histological, metabolic ((18)F-FDG uptake), volumetric (from CT) and molecular (KRAS status) features and long-term outcomes in a homogeneously treated group of patients with locally advanced rectal cancer.

METHODS

HCMV and EBV were detected in pretreatment biopsies using polymerase chain reaction (PCR). The Cox proportional hazards regression model was used to explore associations between viral infection and disease-free survival (DFS) and overall survival (OS).

RESULTS

We analysed 37 patients with a median follow-up of 74 months (range 5-173 months). Locoregional control, OS and DFS at 5 years were 93%, 74% and 71%, respectively. Patients with HCMV/EBV coinfection had a significantly higher maximum standardized uptake value than patients without viral coinfection (p = 0.02). Significant differences were also observed in staging and percentage relative reduction in tumour volume between patients with and without HCMV infection (p < 0.01) and EBV infection (p < 0.01). KRAS wildtype status was significantly more frequently observed in patients with EBV infection (p <0.01) and HCMV/EBV co-infection (p = 0.04). No significant differences were observed in OS or DFS between patients with and without EBV infection (p = 0.88 and 0.73), HCMV infection (p = 0.84 and 0.79), and EBV/CMV coinfection (p = 0.24 and 0.39).

CONCLUSION

This pilot study showed that viral infections were associated with metabolic staging differences, and differences in the evolution of metabolic and volumetric parameters and KRAS mutations. Further findings of specific features will help determine the best candidates for metabolic and volumetric staging and restaging. Further toxicity profile findings will help to determine the best candidates for specific supportive treatment during pelvic chemoradiotherapy in patients with locally advanced rectal cancer.

Klotho suppresses growth and invasion of colon cancer cells through inhibition of IGF1R-mediated PI3K/AKT pathway

Klotho (KL) was originally characterized as an aging suppressor gene, and has been identified as a tumor suppressor gene in a variety of cancers including colon cancer. However, the potential role and molecular events for KL in colon cancer remain unclear. The present study aimed to investigate the expression of KL in human colon cancer by immunohistochemistry, and to analyze the correlation between KL expression and clinicopathological characteristics of patients with colon cancer. Functional analysis after lentivirus-mediated gain of KL expression was used to assess the tumor growth and invasion in colon cancer cells in vitro and in vivo. The rate of KL expression was significantly decreased in cancer tissues compared with that in adjacent non-cancer tissues (ANCT) (60.3 vs.77.9%, P=0.022), and KL expression was negatively associated with Dukes staging (P=0.034) and depth of tumor invasion (P=0.008). Overexpression of KL in vitro inhibited cell proliferative activities and invasive potential in colon cancer cells, companied with decreased expression of p-IGF1R, p-PI3K, p-AKT, PCNA and MMP-2. In addition, the tumor volumes in the HT-29 subcutaneous tumor model treated with lentivirus‑mediated KL vector (Lv-KL) was significantly smaller than those of the negative control (NC) group (P<0.01). Taken together, our findings indicate that the expression of KL is downregulated in human colon caner and correlates with tumor invasion and Dukes staging, while overexpression of KL suppresses growth and invasion through inhibition of IGF1R-mediated PI3K/AKT pathway in colon cancer cells, suggesting that KL may serve as a potential therapeutic target for the treatment of colon cancer.

Effects of silencing RIP1 with siRNA on the biological behavior of the LoVo human colon cancer cell line

The present study aimed to investigate the effects of silencing RIP1 by small interfering RNA (siRNA) on the biological behavior of the LoVo human colorectal carcinoma cell line and to provide evidence for the feasibility of colorectal cancer gene therapy. LoVo cells were divided into the RIP1 siRNA group, the blank control group and the negative control group. Chemically synthesized siRNA targeting RIP1 (RIP1 siRNA) was transfected into LoVo cells. Following transfection of the RIP1-targeted siRNA into the LoVo cells, the expression of the RIP1 gene was effectively inhibited. The results demonstrated that RIP1 effectively regulated the malignant biological behavior of the LoVo colon cancer cell line. Furthermore, the proliferation, motility and invasiveness of LoVo cells were inhibited by siRNA knockdown of RIP1. The results revealed that the RIP1 gene has an important role in the regulation of proliferation and apoptosis in colorectal carcinoma cells.

Fermentation supernatants of Lactobacillus delbrueckii inhibit growth of human colon cancer cells and induce apoptosis through a caspase 3-dependent pathway

Probiotic bacteria are known to exert a wide range of beneficial effects on their animal hosts. Therefore, the present study explored the effect of the supernatants obtained from Lactobacillus delbrueckii fermentation (LBF) on colon cancer. The results indicated that the proliferation of LBF solution-treated colon cancer SW620 cells was arrested and accumulated in the G1 phase in a concentration-dependent manner. The LBF solution efficiently induced apoptosis through the intrinsic caspase 3-depedent pathway, with a corresponding decreased expression of Bcl-2. The activity of matrix metalloproteinase 9, which is associated with the invasion of colon cancer cells, was also decreased in the LBF-treated cells. In conclusion, the results demonstrate the antitumor effect of LBF in vitro and may contribute to the development of novel therapies for the treatment of colon cancer.

Analysis of the intestinal lumen microbiota in an animal model of colorectal cancer

Recent reports have suggested that multiple factors such as host genetics, environment and diet can promote the progression of healthy mucosa towards sporadic colorectal carcinoma. Accumulating evidence has additionally associated intestinal bacteria with disease initiation and progression. In order to examine and analyze the composition of gut microbiota in the absence of confounding influences, we have established an animal model of 1, 2-dimethylhydrazine (DMH)-induced colon cancer. Using this model, we have performed pyrosequencing of the V3 region of the 16S rRNA genes in this study to determine the diversity and breadth of the intestinal microbial species. Our findings indicate that the microbial composition of the intestinal lumen differs significantly between control and tumor groups. The abundance of Firmicutes was elevated whereas the abundance of Bacteroidetes and Spirochetes was reduced in the lumen of CRC rats. Fusobacteria was not detected in any of the healthy rats and there was no significant difference in observed Proteobacteria species when comparing the bacterial communities between our two groups. Interestingly, the abundance of Proteobacteria was higher in CRC rats. At the genus level, Bacteroides exhibited a relatively higher abundance in CRC rats compared to controls (14.92% vs. 9.22%, p<0.001). Meanwhile, Prevotella (55.22% vs. 26.19%), Lactobacillus (3.71% vs. 2.32%) and Treponema (3.04% vs. 2.43%), were found to be significantly more abundant in healthy rats than CRC rats (p<0.001, respectively). We also demonstrate a significant reduction of butyrate-producing bacteria such as Roseburia and Eubacterium in the gut microbiota of CRC rats. Furthermore, a significant increase in Desulfovibrio, Erysipelotrichaceae and Fusobacterium was also observed in the tumor group. A decrease in probiotic species such as Ruminococcus and Lactobacillus was likewise observed in the tumor group. Collectively, we can conclude that a significant difference in intestinal bacterial flora exists between healthy rats and CRC rats.

E. coli and colon cancer: is mutY a culprit?

The recent demonstration of a role of Escherichia coli in the development of invasive carcinoma in mice ushers a new era of bacterial involvement in cancer etiology. It has been shown previously that the colonic mucosa of colorectal carcinoma (CRC) is exclusively colonized by intracellular E. coli instead of extracellular form found in normal colonic mucosa. Surprisingly, the DNA repair gene MUTYH, which is a homologue of the E. coli gene mutY, is responsible for CRC. The current paper discusses the potential role of mutY in CRC etiology and concludes that research in this area can bring together the diverse threads of the CRC etiology puzzle.