[DNA mismatch repair and BRAF status in colorectal cancer: Interest for the therapeutic management?]

Establishment and characterization of a novel human gallbladder cancer cell line, GBC-X1

In this study, we successfully established a novel gallbladder cancer cell line, designated as GBC-X1, derived from a primary tumor of a gallbladder cancer patient. By comprehensively analyzing the cell line's phenotype, molecular characteristics, biomarkers, and histological characteristics, we confirmed that GBC-X1 serves as a valuable model for investigating the pathogenesis of gallbladder cancer and developing therapeutic agents. GBC-X1 has been continuously cultured for one year, with over 60 stable passages. Morphologically, GBC-X1 exhibits typical features of epithelial tumors. The population doubling time of GBC-X1 is 32 h. STR analysis validated a high consistency between GBC-X1 and the patient's primary tumor. Karyotype analysis revealed an abnormal hypertetraploid karyotype for GBC-X1, characterized by representative karyotypes of 98, XXXX del (4) p (12) del (5) p (21) der (10). Under suspension culture conditions, GBC-X1 efficiently forms tumor balls, while subcutaneous inoculation of GBC-X1 cells into NXG mice leads to xenograft formation with a rate of 80%. Drug sensitivity testing demonstrated that GBC-X1 is resistant to oxaliplatin and sensitive to 5-FU, gemcitabine, and paclitaxel. Immunohistochemistry revealed positive expression of CK7, CK19, E-cadherin, MMP-2, CD44, SOX2, and TP53 in GBC-X1 cells, weak positive expression of Vimentin, and a Ki67 positive rate of 35%. Our research highlights GBC-X1 as a novel gallbladder cancer cell line and emphasizes its potential as an effective experimental model for investigating the pathogenesis of gallbladder cancer and drug development.

[Epidemiology of microsatellite instability across solid neoplasms]

Microsatellite instability (MSI) is a predictive biomarker for the efficacy of immune checkpoint inhibitors, regardless of the tumor type. While clinical characteristics of MSI cancer patients have been largely described in tumor localizations frequently associated with this genetic phenotype (i.e. colorectal cancer, endometrial cancer), it remains poorly characterized in other neoplasms. Pan-tumor high-throughput genome sequence analyses have contributed to the broadening of knowledge about the landscape of MSI. This review aims at synthetizing the literature concerning the frequency of MSI status in solid cancers, according to the cancer stage and the hereditary or sporadic origin of the mismatch repair deficiency. We then check for other cancers frequently associated with MSI and describe the clinical and pathological characteristics that should suggest a MSI phenotype.