lncRNA PCAT18 inhibits proliferation, migration and invasion of gastric cancer cells through miR-135b suppression to promote CLDN11 expression.

BACKGROUND: Gastric cancer is a severe disease with a high occurrence rate worldwide. And lncRNAs are demonstrated to be responsible for cancer growth and metastasis. So, it is of great importance to explore the lncRNAs involved mechanism of gastric cancer occurrence and development deeply. METHODS: Transfection was conducted to build over-expression and down-expression models. Moreover, RT-qPCR and western blot were used to detect the transcriptional and translational levels. The biological functions such as proliferation, migration and invasion of AGS cells were evaluated by MTT analysis, colony formation assay, scarification detection and transwell assay, respectively. The potential binding of miR-135b and its downstream and upstream molecules was validated by dual luciferase reporter gene assay or RIP. Also, the in-vivo mice model was further used to demonstrate the role of lncRNA PCAT18 in gastric cancer. RESULTS: PCAT18 down-expression promoted proliferation, migration and invasion of gastric cancer cells. Furtherly, over-expression of miR-135b also promoted these biological characteristics of AGS cells. Importantly, we found that PCAT18 could bind miR-135b which also was bound with CLDN11. We found that miR-135b is negatively correlated with CLDN11; PCAT18 and CLDN11 are positively correlated. Moreover, miR-135b mimics could down-regulate protein level of CLDN11, whereas CLDN11 could reverse this effect. In in-vivo experiment, PCAT18 over-expression restrained tumor growth and metastasis. CONCLUSIONS: Over-expressed lncRNA PCAT18 inhibits proliferation, migration and invasion of gastric cancer cells through regulation of miR-135b/CLDN11.

Establishment of reverse transcription loop-mediated isothermal amplification for rapid detection and differentiation of canine distemper virus infected and vaccinated animals.

Although widespread vaccination against canine distemper virus (CDV) has been conducted for many decades, several canine distemper outbreaks in vaccinated animals have been reported frequently. In order to detect and differentiate the wild-type and vaccine strains of the CDV from the vaccinated animals, a novel reverse transcription loop-mediated isothermal amplification (RT-LAMP) method was developed. A set of four primers-two internal and two external-were designed to target the H gene for the specific detection of wild-type CDV variants. The CDV-H RT-LAMP assay rapidly amplified the target gene, within 60 min, using a water bath held at a constant temperature of 65°C. The assay was 100-fold more sensitive than conventional RT-PCR, with a detection limit of 10(-1)TCID50ml(-1). The system showed a preference for wild-type CDV, and exhibited less sensitivity to canine parvovirus, canine adenovirus type 1 and type 2, canine coronavirus, and canine parainfluenza virus. The assay was validated using 102 clinical samples obtained from vaccinated dog farms, and the results were comparable to a multiplex nested RT-PCR assay. The specific CDV-H RT-LAMP assay provides a simple, rapid, and sensitive tool for the detection of canines infected with wild-type CDV from canines vaccinated with attenuated vaccine.

[Expression of CD71 on cell proliferation in hematologic malignancy and its correlation with Ki-67].

OBJECTIVE: This study was to explore the expression of CD71, as a proliferation indicator, on cell proliferaration in hematologic malignancy and its correlation with Ki-67, so as to assess the feasibility of CD71 instead of Ki-67 for assaying cell proliferation by flow cytometry (FCM). METHODS: (1) Compared with mature B lymphoctyes during stationary phase in peripheral blood from healthy people, the cell cycle and the expression of CD71 and Ki-67 of cell lines from patients with leukemia and lymphoma were examined, the correlation among CD71, S-phase cell fraction (SPF) and Ki-67 were analyzed; (2) Compared with mature B lymphoctyes in bone marrow from non-hematologic disease patients, the expression and correlation of CD71 and Ki-67 of all kinds of leukemic cells and myeloma cells from bone marrow were analyzed by using Ki-67/CD71/CD45/CD123, Ki-67/CD71/CD45/CD20 or Ki-67/CD71/CD45/CD138. RESULTS: (1) in respect to the expression rate of CD71 on tumor cell lines, the expression rate of CD71 on HL-60 cells was (99.77 ± 0.064)%, the expression rate of CD71 on NB4 cells was (99.23 ± 0.12)%, the expression rate on THP-1 cells was (98.90 ± 0.30)% and the expression rate on K562 cells was (97.03 ± 0.15)% in myelogenous leukemia cell lines, the expression rate of CD71 on Raji cells was (99.35 ± 0.21)% and the expression rate on Mino cell was (96.95 ± 0.42)% in lymphoma cell lines, which were also obviously higher than that on cells of the control group (P < 0.05); (2) in respect to the expression rate of CD71 on tumor cells in bone marrow, the expression rate of CD71 on poorly differentiated AML(M1 and M2) cells was (51.50 ± 19.31)%, the expression rate of CD71 on acute promyelocytic leukemia (AML-M3) cells was (35.71 ± 14.02) %, the expression rate of CD71 on acute monocytic leukemia (AML-M5) cells was (30.54 ± 14.38)%, the expression rate of CD71 on acute T lymphoblastic leukemia cells was (68.40 ± 20.83)%, the expression rate of CD71 on acute B lymphoblastic leukemia was (39.67 ± 18.27)%, the expression rate of CD71 on multiple myeloma (MM) cells was (55.49 ± 18.15%), the expression rate of CD71 on chronic lymphocytic leukemia(CLL) was (1.32 ± 0.33%), which were also higher than that on cells in the control group(P < 0.05) except for CLL cells (P > 0.05); (3) CD71 had a positive linear corrlation with SPF in cell lines (r = 0.914, P < 0.05), and also had a positive linear corrlation with Ki-67 in cell lines and carcinoma cells from bone marrow (r = 0.894,r = 0.904, P < 0.05). CONCLUSION: The CD71 can take the place of Ki-67 as an indicator of cell proliferation activity of hematologic malignancies and the determination CD71 by FCM is simpler and better than that of Ki-67 in respest of methodology.

[Therapeutic effects of systemic chemotherapy on advanced pancreatic cancer patients].

BACKGROUND & OBJECTIVE: Advanced,unresectable pancreatic cancer is an extremely aggressive disease. Systemic chemotherapy is the most frequently administered treatment for the patients with advanced pancreatic cancer. This clinical trial was designed to compare the efficacy, clinical benefit response (CBR), and toxicity profile of three regimens in treating advanced pancreatic cancer (APC). METHODS: From February 2000 to April 2001,74 patients of pathologically advanced pancreatic cancer were analyzed retrospectively. Of 74 APC patients, 26 received 5-fluorouracil+leucovorin+cisplatin (Arm A), 23 received gemcitabine (Arm B) and 25 treated with gemcitabine+5-fluorouracil+leucovorin (Arm C). Kaplan-Meier method was used for analysis of survival rate and Cox regression model was used for analysis of prognostic factors. RESULTS: The overall response rates and CBRs were 7.69% and 19.23% in Arm A, 17.39% and 47.83% in Arm B, 24.0% and 60.0% in Arm C. There was no significant difference in the overall response rate(P=0.261,Chi-square test) and a significant difference in CBR among three groups(P< 0.05, Chi-square test). The median survival time were 6.5 months for Arm A(95%CI 5.00,7.99 months),8.03 months for Arm B(95%CI 6.72,9.35 months) and 8.79 months for Arm C (95%CI 7.31,10.26 months). There were significant differences among three groups in the median survival time(Breslow=8.85,P=0.0119). There was no significant difference in the incidence of hematological and nonhematological toxicity among three groups. CONCLUSION: The combination of gemcitabine,5-fluorouracil and leucovorin is a moderatedly active treatment with tolerable side effects. It has definite response rate and also significantly improve the quality of life in patients. Its treatment value is worth further studying.