Biology subjects

Lozano-Pope, I.

Publications and source records attributed to Lozano-Pope, I..

3 recordsLinked to original sources

bioRxiv2025

Gastric cancer treatment target identified from an accelerated Helicobacter-induced gastric cancer mouse model

Helicobacter pylori (H. pylori) infection and consequent inflammation leads to gastric cancer (GC). Despite the prevalence of this bacterium and availability of genomic data, targeted therapies for GC are still early in development. Previously in our accelerated Helicobacter-induced gastric cancer mouse model we identified several differentially expressed genes (DEGs), including PSMB8 (proteasome subunit beta type 8, also called LMP7); one of the immune subunits of the immunoproteasome, which has been associated with disease severity in multiple cancers. We observed elevated expression of PSMB8 in our accelerated gastric cancer model, in the human gastric cancer cell line (MKN45), and in gastric cancer patient samples. Moreover, we identified carfilzomib as a potential drug that targets PSMB8. Therefore, to test its efficacy against gastric cancer, nude mice were subcutaneously implanted with MKN45 derived tumors and treated with carfilzomib, alone or in combination with 5-fluorouracil (5-FU), the standard care drug. The effectiveness of drug treatment was measured by tumor growth, cell proliferation, and apoptosis. We observed that carfilzomib retarded tumor growth, inhibited cell proliferation and induced apoptosis. These results strongly suggest that carfilzomib has a robust anti-tumor activity and is a suitable drug candidate for targeted therapy in gastric cancer.

cancer biology↗

bioRxiv2023

Activation of the TRIF pathway and downstream targets results in the development of precancerous lesions during infection with Helicobacter.

Helicobacter pylori (H. pylori) infection is an established cause of many digestive diseases, including gastritis, peptic ulcers, and gastric cancer. However, the mechanism by which infection with H. pylori causes these disorders is still not clearly understood. This is due to insufficient knowledge of pathways that promote H. pylori-induced disease progression. We have established a Helicobacter-induced accelerated disease progression mouse model, which involves infecting mice deficient in the myeloid differentiation primary response 88 gene (Myd88-/-) with H. felis. Using this model, we report here that that progression of H. felis-induced inflammation to high-grade dysplasia was associated with activation of type I interferon (IFN-I) signaling pathway and upregulation of related downstream target genes, IFN-stimulated genes (ISGs). These observations were further corroborated by the enrichment of ISRE motifs in the promoters of upregulated genes. Further we showed that H. felis-induced inflammation in mice deficient in Toll/interleukin-1 receptor (TIR)-domain-containing adaptor inducing interferon-{beta} (TRIF, TrifLps2) did not progress to severe gastric pathology, indicating a role of the TRIF signaling pathway in disease pathogenesis and progression. Indeed, survival analysis in gastric biopsy samples from gastric cancer patients illustrated that high expression of Trif was significantly associated with poor survival in gastric cancer.

cancer biology↗

bioRxiv2020

Early detection of biomarkers for circulating tumor cells in Bone marrow and Peripheral blood in a fast-progressing gastric cancer model.

Helicobacter pylori poses one of the greatest risks for development of gastric cancer. We previously established a crucial role for myeloid differentiation primary response 88 (MyD88) in the regulation of Helicobacter-induced gastric cancer. Mice deficient in Myd88 rapidly progressed to neoplasia when infected with H. felis, a close relative of H. pylori. For this study we examined circulating tumor cells (CTCs) by measuring expression of cytokeratins, epithelial to mesenchymal transition (EMT) and cancer stem cell (CSC) markers in in the bone marrow and peripheral blood of gastric cancer models we termed fast (Myd88-/-)- and slow (WT)-"progressors". We detected cytokeratins CK8/18 as early as 3 months post infection in the fast "progressors". In contrast, cytokeratins were not detected in slow "progressor" gastric cancer model even after 7 months post infection. Expression of 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. Expression of these EMT markers suggests manifestation of cancer metastasis in the early stages of disease development. Lgr5, CD44 and CD133 were the most prominent CSC markers detected. 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 will be important in stratifying patients for treatment before the onset of severe disease characteristics.

cancer biology↗