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 non-obese 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.

Tunable spatiotemporal mode-locked fiber laser at 1.55 µm.

We report the spatiotemporal mode-locked multimode fiber laser operating at 1.55 µm based on semiconductor saturable absorber mirrors with the mode-locking threshold as low as 104 mW. Benefiting from the multimode interference filtering effect introduced in the laser cavity not only the central wavelength can be continuously tuned from 1557 nm to 1567 nm, but also the number of the output pulses can be adjusted from 1 to 4 by simply adjusting the polarization controllers. This work provides a new platform for exploring the dynamic characteristics of spatiotemporal mode-locked pulses at negative dispersion regime. Moreover, this kind of tunable laser has potential applications in fields of all-optical signal processing, fiber sensing and information coding.

Dicer1/miR-29/HMGCR axis contributes to hepatic free cholesterol accumulation in mouse non-alcoholic steatohepatitis.

Dicer1 is an enzyme essential for microRNA (miRNA) maturation. The loss of miRNAs resulted from Dicer1 deficiency greatly contributes to the progression of many diseases, including lipid dysregulation, but its role in hepatic accumulation of free cholesterol (FC) that is critical in the development of non-alcoholic steatohepatitis (NASH) remains elusive. In this study, we used the liver-specific Dicer1-knockout mice to identify the miRNAs involved in hepatic FC accumulation. In a widely used dietary NASH model, mice were fed a methionine-choline-deficient (MCD) diet for 3 weeks, which resulted in significant increase in hepatic FC levels as well as decrease of Dicer1 mRNA levels in livers. The liver-specific Dicer1-knockout induced hepatic FC accumulation at 5-6 weeks, accompanied by increased mRNA and protein levels of 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGCR), a rate-limiting enzyme of cholesterol synthesis in livers. Eleven predicted miRNAs were screened, revealing that miR-29a/b/c significantly suppressed HMGCR expression by targeting the HMGCR mRNA 3'-UTR. Overexpression of miR-29a in SMMC-7721 cells, a steatosis hepatic cell model, significantly decreased HMGCR expression and the FC level. Furthermore, the expression levels of miR-29a were inversely correlated with HMGCR expression levels in the MCD diet mouse model in vivo and in 2 steatosis hepatic cell models (SMMC-7721 and HL-7702 cells) in vitro. Our results show that Dicer1/miR-29/HMGCR axis contributes to hepatic free cholesterol accumulation in mouse NASH, and miR-29 may serve as an important regulator of hepatic cholesterol homeostasis. Thus, miR-29a could be utilized as a potential therapeutic target for the treatment of non-alcoholic fatty liver disease as well as for other liver diseases associated with FC accumulation.

MicroRNA-1304 suppresses human non-small cell lung cancer cell growth in vitro by targeting heme oxygenase-1.

Previous studies have shown that microRNA-1304 (miR-1304) is dysregulated in certain types of cancers, including non-small cell lung cancer (NSCLC), and might be involved in tumor survival and/or growth. In this study we investigated the direct target of miR-1304 and its function in NSCLC in vitro. Human lung adenocarcinoma cell lines (A549 and NCI-H1975) were studied. The cell proliferation and survival were investigated via cell counting, MTT and colony-formation assays. Cell apoptosis and cell cycle were examined using annexin V-PE/7-AAD and PI staining assays, respectively. The dual-luciferase reporter assay was used to verify post-transcriptional regulation of heme oxygenase-1 (HO-1) by miR-1304. CRISPR/Cas9 was used to deplete endogenous miR-1304. Overexpression of MiR-1304 significantly decreased the number and viability of NSCLC cells and colony formation, and induced cell apoptosis and G0/G1 phase cell cycle arrest. HO-1 was demonstrated to be a direct target of miR-1304 in NSCLC cells. Restoration of HO-1 expression by hemin (20 µmol/L) abolished the inhibition of miR-1304 on cell growth and rescued miR-1304-induced apoptosis in A549 cells. Suppression of endogenous miR-1304 with anti-1304 significantly increased HO-1 expression and promoted cell growth and survival in A549 cells. In 17 human NSCLC tissue samples, miR-1304 expression was significantly decreased, while HO-1 expression was significantly increased as compared to normal lung tissues. MicroRNA-1304 is a tumor suppressor and HO-1 is its direct target in NSCLC. The results suggest the potential for miR-1304 as a therapeutic target for NSCLC.

[Differences in the changes of blood clotting state after initial trauma fractures and twice trauma fractures].

OBJECTIVE: To compare changes of blood clotting state after initial trauma fractures and twice trauma fractures, investigate the effect of fracture history to the state of the blood clotting after secondary trauma fractures. METHODS: Thirty New Zealand rabbits were selected, aged 5-6 months, males and females unlimited, weighted 2.4-2.6 kg, non-pregnant. Postoperative model of initial trauma fractures was established, and then postoperative model after twice trauma fractures was built. Prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time (TT), fiber fibrinogen (FIB) and D-dimer (DD) were detected by venous blood at 1 day and 5 days after surgery. Changes of indicators were compared between after twice fractures at the same time. RESULTS: Comparing with 1 day after the secondary trauma fracture and initial trauma fracture surgery, PT, APTT values showed no significant difference (P > 0.05), TT, FIB, DD values were increased, and the difference was statistically significant (P < 0.05); Comparing with 5 days after the secondary trauma fracture and initial trauma fracture surgery, PT values showed no significant difference (P < 0 .05), APTT, TT, FIB, DD values were increased, and the difference was statistically significant (P< 0.05). CONCLUSION: Blood after the secondary trauma fractures is in hypercoagulable state after fracture surgery.