First report on establishment and characterization of the extrahepatic cholangiocarcinoma sarcoma cell line CBC2T-2

BACKGROUND Extrahepatic cholangiocarcinoma sarcoma is extremely rare in clinical practice.These cells consist of both epithelial and mesenchymal cells.Patient-derived cell lines that maintain tumor characteristics are valuable tools for studying the molecular mechanisms associated with carcinosarcoma.However,cholangiocarcinoma sarcoma cell lines are not available in cell banks.AIM To establish and characterize a new extrahepatic cholangiocarcinoma sarcoma cell line,namely CBC2T-2.METHODS We conducted a short tandem repeat(STR)test to confirm the identity of the CBC2T-2 cell line.Furthermore,we assessed the migratory and invasive properties of the cells and performed clonogenicity assay to evaluate the ability of individual cells to form colonies.The tumorigenic potential of CBC2T-2 cells was tested in vivo using nonobese diabetic/severe combined immunodeficient(NOD/SCID)mice.The cells were injected subcutaneously and tumor formation was observed.In addition,immunohistochemical analysis was carried out to examine the expression of epithelial marker CK19 and mesenchymal marker vimentin in both CBC2T-2 cells and xenografts.The CBC2T-2 cell line was used to screen the potential therapeutic effects of various clinical agents in patients with cholangiocarcinoma sarcoma.Lastly,whole-exome sequencing was performed to identify genetic alterations and screen for somatic mutations in the CBC2T-2 cell line.RESULTS The STR test showed that there was no cross-contamination and the results were identical to those of the original tissue.The cells showed round or oval-shaped epithelioid cells and mesenchymal cells with spindle-shaped or elongated morphology.The cells exhibited a high proliferation ratio with a doubling time of 47.11 h.This cell line has migratory,invasive,and clonogenic abilities.The chromosomes in the CBC2T-2 cells were polyploidy,with numbers ranging from 69 to 79.The subcutaneous tumorigenic assay confirmed the in vivo tumorigenic ability of CBC2T-2 cells in NOD/SCID mice.CBC2T-2 cells and xenografts were positive for both the epithelial marker,CK19,and the mesenchymal marker,vimentin.These results suggest that CBC2T-2 cells may have both epithelial and mesenchymal characteristics.The cells were also used to screen clinical agents in patients with cholangiocarcinoma sarcoma,and a combination of paclitaxel and gemcitabine was found to be the most effective treatment option.CONCLUSION We established the first human cholangiocarcinoma sarcoma cell line,CBC2T-2,with stable biogenetic traits.This cell line,as a research model,has a high clinical value and would facilitate the understanding of the pathogenesis of cholangiocarcinoma sarcoma.

Effect of KIF22 on promoting proliferation and migration of gastric cancer cells via MAPK-ERK pathways

Background:Gastric cancer (GC) is one of the most globally prevalent cancers in the world. The pathogenesis of GC has not been fully elucidated, and there still lacks effective targeted therapeutics. The influence of altered kinesin superfamily protein 22 (KIF22) expression in GC progression is still unclearly. The aim of this study was to investigate the KIF22 effects on GC and related mechanisms.Methods:Gastric carcinoma tissues and matching non-cancerous tissues were collected from patients with GC who have accepted a radical gastrectomy in Lanzhou University Second Hospital from May 2013 to December 2014. The expression of KIF22 was examined in GC of 67 patients and 20 para-carcinoma tissues by immunochemical staining. The relationship between the expression of KIF22 and clinicopathologic characteristics was next investigated in the remaining 52 patients except for 15 patients who did not complete follow-up for 5 years. Cell viability was performed via 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) test and colony formation assay in the MGC-803 and BGC-823 GC cells. Cell scratch and trans-well invasion assay was performed to assess migration ability in the MGC-803 and BGC-823 GC cells. Gene set enrichment analysis (GSEA) pathway enrichment analysis was performed to explore the potential functions. Cell cycle was detected by flow cytometry. In addition, the two GC cell lines were used to elucidate the underlying mechanism of KIF22 in GC in vitro via assessing the effects on mitogenactivated protein kinase and extracellular regulated protein kinases (MAPK/ERK) signal transduction pathway-related expressions by Western blotting assays. The differences were compared by t tests, one-way analysis of variance, and Chi-squared tests. Results:The study showed that KIF22 was up-regulated in GC, and KIF22 high expression was significantly related to differentiation degree ( χ2 = 12.842, P = 0.002) and poorly overall survivals. GSEA pathway enrichment analysis showed that KIF22 was correlated with the cell cycle. Silence of KIF22 decreased the ability of the proliferation and migration in gastric cells, induced G1/S phase cell cycle arrest via regulating the MAPK-ERK pathways. Conclusions:KIF22 protein level was negatively correlated with prognosis. KIF22 knockdown might inhibit proliferation and metastasis of GC cells via the MAPK-ERK signaling pathway.

Function of Rho GTPase Activating Protein 11A in Tumors

To the Editor： Rho GTPase Activating Protein 1 IA （ArhGAPllA） is a member of the Rho GTPase-activating proteins （Rho GAPs） gene family and is located on the long arm of 15 chromosome region 1 band 3 subband 2 （ 15q 13.3）. The full-length cDNA of ArhGAPIIA is 24,806 bp with a single open-reading frame. ArhGAPIIA is encoded by 13 exons and the encoded protein has three domains： a RhoGAP domain near the N terminus （amino acids 46-246）, and two uncharacterized domains respectively located in the center （387 516） and C terminus （590-997） of the protein.