Characterization of acquired capecitabine resistance in MKN-45 gastric cancer cells reveals preserved apoptotic sensitivity.
Capecitabine (Cap) is widely used in the treatment of advanced gastric cancer; however, the emergence of acquired resistance remains a major obstacle to its long-term efficacy. Although several gastric cancer models resistant to 5-fluorouracil (5-FU) have been reported, experimentally characterized gastric cancer models of Cap resistance remain limited.
This study aimed to establish and characterize a Cap-resistant MKN-45 gastric cancer cell model. with a focus on phenotypic alterations associated with acquired drug adaptation.
A Cap-resistant MKN-45 subline (MKN-45/R-CapIC₆₀) was generated through exposure of parental MKN-45 cells to gradually increasing concentrations of Cap. Cell viability was evaluated using the MTT assay. Morphological alterations were examined by phase-contrast microscopy, while apoptosis, cell-cycle distribution, and surface c-Met expression were analyzed by flow cytometry.
The established resistant subline exhibited a moderate level of Cap resistance, with an approximately 2- to 4-fold increase in the resistance index (RI) compared with the parental cells. Resistant cells showed morphological remodeling characterized by an elongated spindle-like morphology and increased adherence to the culture surface compared with parental cells. Surface c-Met expression was altered in resistant cells and further decreased following Cap exposure. Despite the acquisition of a resistance phenotype, Cap exposure retained biological activity in resistant cells by reducing proliferation, altering cell-cycle distribution through impaired G1/S transition, and increasing late apoptotic/necrotic populations.
The findings suggest that the established Cap-resistant gastric cancer cell model retains responsiveness to Cap exposure despite the acquisition of a resistance phenotype. This model may provide a useful platform for investigating early phenotypic adaptations associated with the development of drug resistance in gastric cancer.
This study aimed to establish and characterize a Cap-resistant MKN-45 gastric cancer cell model. with a focus on phenotypic alterations associated with acquired drug adaptation.
A Cap-resistant MKN-45 subline (MKN-45/R-CapIC₆₀) was generated through exposure of parental MKN-45 cells to gradually increasing concentrations of Cap. Cell viability was evaluated using the MTT assay. Morphological alterations were examined by phase-contrast microscopy, while apoptosis, cell-cycle distribution, and surface c-Met expression were analyzed by flow cytometry.
The established resistant subline exhibited a moderate level of Cap resistance, with an approximately 2- to 4-fold increase in the resistance index (RI) compared with the parental cells. Resistant cells showed morphological remodeling characterized by an elongated spindle-like morphology and increased adherence to the culture surface compared with parental cells. Surface c-Met expression was altered in resistant cells and further decreased following Cap exposure. Despite the acquisition of a resistance phenotype, Cap exposure retained biological activity in resistant cells by reducing proliferation, altering cell-cycle distribution through impaired G1/S transition, and increasing late apoptotic/necrotic populations.
The findings suggest that the established Cap-resistant gastric cancer cell model retains responsiveness to Cap exposure despite the acquisition of a resistance phenotype. This model may provide a useful platform for investigating early phenotypic adaptations associated with the development of drug resistance in gastric cancer.
Authors
Mohseni Mohseni, Tavajohi Tavajohi, Kebriaeezadeh Kebriaeezadeh, Ghahremani Ghahremani, Ostad Ostad
View on Pubmed