Efficacy of bevacizumab-containing chemotherapy in metastatic colorectal cancer and CXCL5 expression: Six case reports

BACKGROUND In metastatic colorectal cancer(mCRC),the anti-vascular endothelial growth factor drug bevacizumab(BVZ)plus chemotherapy significantly improves progression-free survival compared to chemotherapy(CT)alone.This benefit is not,however,observed in all patients.While increased chemokine CXCL5 gene expression promoting angiogenesis has been proposed as a prognostic mCRC biomarker,few studies have examined its relationship with drug efficacy.This study sought to analyze tumor CXCL5 gene expression in six patients with different efficacy of BVZ-containing CT in terms of the tumor response to treatment.CASE SUMMARY We report six cases of stage IV KRAS-mutated mCRC.Patients were given first line treatment with BVZ-containing chemotherapy in University Hospital of Fuenlabrada.The six patients differed in terms of primary tumor location(right/left side),tumor burden(mostly hepatic and peritoneal disease)and clinical disease course.Before treatment onset,total RNA was isolated from paraffinated tumor biopsy specimens and CXCL5 gene expression quantified through conventional RT-qPCR procedures.Our main finding was that CXCL5 expression levels were several times higher in three patients with lower progression free survival(under 6 mo)from the start of treatment.CONCLUSION A higher expression of CXCL5 was observed in the three patients showing worse tumor response to treatment.

The growth of Staphylococcus aureus and Escherichia coli in low-direct current electric fields

Electrical potentials up to 800 mV can be observed between different metallic dental restorations. These potentials produce fields in the mouth that may interfere with microbial communities. The present study focuses on the impact of different electric field strengths （EFS） on the growth of Staphylococcus aureus （ATCC 25923） and Escherichia coil （ATCC 25922） in vitro. Cultures of S. aureus and E. coil in fluid and gel medium were exposed to different EFS. Effects were determined by calculation of viable counts and measurement of inhibition zones. In gel medium, anodic inhibition zones for S. aureuswere larger than those for E. coliat all field strength levels. In fluid medium, the maximum decrease in the viable count of S. aureus cells was at 10 V.m-1. Field-treated S. aureus cells presented ruptured cell walls and disintegrated cytoplasm. Conclusively, S. aureus is more sensitive to increasing electric field strength than E. coll.