Effect of myeloid differentiation primary response gene 88 on expression profiles of genes during the development and progression of Helicobacter-induced gastric cancer

Downregulated biological processes and molecular functions in Myd88 −/− mice. Enriched Go terms are shown at both 25 (A, B) and 47 weeks (C, D). Biological processes are depicted in figures A and C while molecular functions are depicted in B and D. These functions were identified using STRING functional annotation tool. Relative scores were calculated using the number of genes found within each process relative to the total number of genes entered into the annotation tool. The top 20 Biological Processes are shown. (PPTX 482 kb

Myeloid Differentiation Primary Response Gene 88 Is Required for the Resolution of Otitis Media

Signaling defects in the Toll-like receptor (TLR) pathway, such as interleukin-1 receptor–associated kinase 4 deficiency, highlight the prominence of TLR signaling in the defense against bacterial disease. Because myeloid differentiation primary response gene 88 (MyD88) can transduce signals from almost all TLRs, we studied its role in otitis media (OM), the most common upper respiratory tract bacterial infectious disease in young children

Early detection of tumor cells in bone marrow and peripheral blood in a fast‑progressing gastric cancer model.

Helicobacter pylori (H. pylori) infection is a major risk factor for the development of gastric cancer. The authors previously demonstrated that in mice deficient in myeloid differentiation primary response 88 (Myd88‑/‑), infection with Helicobacter felis (H. felis) a close relative of H. pylori, subsequently rapidly progressed to neoplasia. The present study examined circulating tumor cells (CTCs) by measuring the expression of cytokeratins, epithelial‑to‑mesenchymal transition (EMT)‑related markers and cancer stem cell (CSC) markers in bone marrow and peripheral blood from Myd88‑/‑ and wild‑type (WT) mice. Cytokeratins CK8/18 were detected as early as 4 months post‑infection in Myd88‑/‑ mice. By contrast, cytokeratins were not detected in WT mice even after 7 months post‑infection. The expression of Mucin‑1 (MUC1) was observed in both bone marrow and peripheral blood at different time points, suggesting its role in gastric cancer metastasis. Snail, Twist and ZEB were expressed at different levels in bone marrow and peripheral blood. The expression of these EMT‑related markers suggests the manifestation of cancer metastasis in the early stages of disease development. LGR5, CD44 and CD133 were the most prominent CSC markers detected. The detection of CSC and EMT markers along with cytokeratins does reinforce their use as biomarkers for gastric cancer metastasis. This early detection of markers suggests that CTCs leave primary site even before cancer is well established. Thus, cytokeratins, EMT, and CSCs could be used as biomarkers to detect aggressive forms of gastric cancers. This information may prove to be of significance in stratifying patients for treatment prior to the onset of severe disease‑related characteristics

A Bioluminescence-Based Drug Screen Identifies Activities of Fexinidazole and Its Metabolites against Helicobacter pylori.

Helicobacter pylori is responsible for a wide range of gastric diseases, including gastric cancer and gastritis. With half of the worlds population infected by H. pylori and the current standard of care associated with suboptimal outcomes, a search for more effective drugs is critical. To facilitate drug screening for H. pylori, we developed a microtiter plate-based compound screening method that is faster and can screen multiple compounds. We identified activities of fexinidazole and its sulfoxide and sulfone metabolites against H. pylori. Both fexinidazole and its metabolites exhibited equipotency against SS1, 60190, and G27 strains, which were about 3-6-fold more potent than the currently used metronidazole. We also determined the minimal inhibitory concentration (MIC) of metronidazole, fexinidazole, and its metabolites against these strains by a traditional agar plate-based method. While MIC values of fexinidazole and metronidazole were similar against all the strains, both sulfoxide and sulfone showed lower MIC values than metronidazole against SS1 and 60190. Given the recent FDA approval of fexinidazole, our data on the in vitro antibacterial activities of fexinidazole and its metabolites support further evaluation of this drug with the goal of producing an alternative nitro-based antimicrobial with good safety profiles for the treatment of H. pylori infection

A Bioluminescence-Based Drug Screen Identifies Activities of Fexinidazole and Its Metabolites against <i>Helicobacter pylori</i>

Helicobacter pylori is responsible for a wide range of gastric diseases, including gastric cancer and gastritis. With half of the world’s population infected by H. pylori and the current standard of care associated with suboptimal outcomes, a search for more effective drugs is critical. To facilitate drug screening for H. pylori, we developed a microtiter plate-based compound screening method that is faster and can screen multiple compounds. We identified activities of fexinidazole and its sulfoxide and sulfone metabolites against H. pylori. Both fexinidazole and its metabolites exhibited equipotency against SS1, 60190, and G27 strains, which were about 3–6-fold more potent than the currently used metronidazole. We also determined the minimal inhibitory concentration (MIC) of metronidazole, fexinidazole, and its metabolites against these strains by a traditional agar plate-based method. While MIC values of fexinidazole and metronidazole were similar against all the strains, both sulfoxide and sulfone showed lower MIC values than metronidazole against SS1 and 60190. Given the recent FDA approval of fexinidazole, our data on the in vitro antibacterial activities of fexinidazole and its metabolites support further evaluation of this drug with the goal of producing an alternative nitro-based antimicrobial with good safety profiles for the treatment of H. pylori infection

Microbiome Signatures in a Fast- and Slow-Progressing Gastric Cancer Murine Model and Their Contribution to Gastric Carcinogenesis

Gastric cancer is the third most common cause of death from cancer in the world and infection with Helicobacterpylori (H. pylori) is the main cause of gastric cancer. In addition to Helicobacter infection, the overall stomach microbiota has recently emerged as a potential factor in gastric cancer progression. Previously we had established that mice deficient in myeloid differentiation primary response gene 88 (MyD88, Myd88&minus;/&minus;) rapidly progressed to neoplasia when infected with H. felis. Thus, in order to assess the role of the microbiota in this fast-progressing gastric cancer model we investigated changes of the gastric microbiome in mice with different genotypic backgrounds: wild type (WT), MyD88-deficient (Myd88&minus;/&minus;), mice deficient in the Toll/interleukin-1 receptor (TIR) domain-containing adaptor-inducing interferon-&beta; (TRIF, TrifLps2), and MyD88- and TRIF-deficient (Myd88&minus;/&minus;/TrifLps2, double knockout (DKO)) mice. We compared changes in alpha diversity, beta diversity, relative abundance, and log-fold differential of relative abundance ratios in uninfected and Helicobacter infected mice and studied their correlations with disease progression to gastric cancer in situ. We observed an overall reduction in microbial diversity post-infection with H. felis across all genotypes. Campylobacterales were observed in all infected mice, with marked reduction in abundance at 3 and 6 months in Myd88&minus;/&minus; mice. A sharp increase in Lactobacillales in infected Myd88&minus;/&minus; and DKO mice at 3 and 6 months was observed as compared to TrifLps2 and WT mice, hinting at a possible role of these bacteria in gastric cancer progression. This was further reinforced upon comparison of Lactobacillales log-fold differentials with histological data, indicating that Lactobacillales are closely associated with Helicobacter infection and gastric cancer progression. Our study suggests that differences in genotypes could influence the stomach microbiome and make it more susceptible to the development of gastric cancer upon Helicobacter infection. Additionally, increase in Lactobacillales could contribute to faster development of gastric cancer and might serve as a potential biomarker for the fast progressing form of gastric cancer

Microbiome Signatures in a Fast- and Slow-Progressing Gastric Cancer Murine Model and Their Contribution to Gastric Carcinogenesis.

Gastric cancer is the third most common cause of death from cancer in the world and infection with Helicobacter pylori (H. pylori) is the main cause of gastric cancer. In addition to Helicobacter infection, the overall stomach microbiota has recently emerged as a potential factor in gastric cancer progression. Previously we had established that mice deficient in myeloid differentiation primary response gene 88 (MyD88, Myd88-/- ) rapidly progressed to neoplasia when infected with H. felis. Thus, in order to assess the role of the microbiota in this fast-progressing gastric cancer model we investigated changes of the gastric microbiome in mice with different genotypic backgrounds: wild type (WT), MyD88-deficient (Myd88-/- ), mice deficient in the Toll/interleukin-1 receptor (TIR) domain-containing adaptor-inducing interferon-β (TRIF, Trif Lps2), and MyD88- and TRIF-deficient (Myd88-/- /Trif Lps2, double knockout (DKO)) mice. We compared changes in alpha diversity, beta diversity, relative abundance, and log-fold differential of relative abundance ratios in uninfected and Helicobacter infected mice and studied their correlations with disease progression to gastric cancer in situ. We observed an overall reduction in microbial diversity post-infection with H. felis across all genotypes. Campylobacterales were observed in all infected mice, with marked reduction in abundance at 3 and 6 months in Myd88-/- mice. A sharp increase in Lactobacillales in infected Myd88-/- and DKO mice at 3 and 6 months was observed as compared to Trif Lps2 and WT mice, hinting at a possible role of these bacteria in gastric cancer progression. This was further reinforced upon comparison of Lactobacillales log-fold differentials with histological data, indicating that Lactobacillales are closely associated with Helicobacter infection and gastric cancer progression. Our study suggests that differences in genotypes could influence the stomach microbiome and make it more susceptible to the development of gastric cancer upon Helicobacter infection. Additionally, increase in Lactobacillales could contribute to faster development of gastric cancer and might serve as a potential biomarker for the fast progressing form of gastric cancer

Comparison of lipopolysaccharides composition of two different strains of Helicobacter pylori

BackgroundHelicobacter pylori (H. pylori) is a Gram-negative, microaerophilic bacterium that is recognized as a major cause of chronic gastritis, peptic ulcers, and gastric cancer. Comparable to other Gram-negative bacteria, lipopolysaccharides (LPS) are an important cellular component of the outer membrane of H. pylori. The LPS of this organism plays a key role in its colonization and persistence in the stomach. In addition, H. pylori LPS modulates pathogen-induced host inflammatory responses resulting in chronic inflammation within the gastrointestinal tract. Very little is known about the comparative LPS compositions of different strains of H. pylori with varied degree of virulence in human. Therefore, LPS was analyzed from two strains of H. pylori with differing potency in inducing inflammatory responses (SS1 and G27). LPS were extracted from aqueous and phenol layer of hot-phenol water extraction method and subjected for composition analysis by gas chromatography - mass spectrometry (GC-MS) to sugar and fatty acid compositions.ResultsThe major difference between the two strains of H. pylori is the presence of Rhamnose, Fucose and GalNAc in the SS1 strain, which was either not found or with low abundance in the G27 strain. On the other hand, high amount of Mannose was present in G27 in comparison to SS1. Fatty acid composition of lipid-A portion also showed considerable amount of differences between the two strains, phenol layer of SS1 had enhanced amount of 3 hydroxy decanoic acid (3-OH-C10:0) and 3-hydroxy dodecanoic acid (3-OH-C12:0) which were not present in G27, whereas myristic acid (C14:0) was present in G27 in relatively high amount.ConclusionThe composition analysis of H. pylori LPS, revealed differences in sugars and fatty acids composition between a mouse adapted strain SS1 and G27. This knowledge provides a novel way to dissect out their importance in host-pathogen interaction in further studies