Evaluation of reporting quality of abstracts of randomized controlled trials regarding patients with COVID-19 using the CONSORT statement for abstracts.

OBJECTIVE: To evaluate the reporting quality of randomized controlled trial (RCT) abstracts regarding patients with coronavirus disease 2019 (COVID-19) and to analyze the factors influencing the quality. METHODS: The PubMed, Embase, Web of Science, and Cochrane Library databases were searched to collect RCTs on patients with COVID-19. The retrieval time was from inception to December 1, 2020. The CONSORT statement for abstracts was used to evaluate the reporting quality of RCT abstracts. RESULTS: A total of 53 RCT abstracts were included. The CONSORT statement for abstracts showed that the average reporting rate of all items was 50.2%. The items with a lower reporting quality were mainly the trial design and the details of randomization and blinding (<10%). The mean overall adherence score across all studies was 8.68 ± 2.69 (range 4-13.5). Multivariate linear regression analysis showed that the higher reporting scores were associated with higher journal impact factor (P < 0.01), international collaboration (P = 0.04), and structured abstract format (P < 0.01). CONCLUSIONS: Although many RCTs on patients with COVID-19 have been published in different journals, the overall quality of reporting in the included RCT abstracts was suboptimal, thus diminishing their potential usefulness, and this may mislead clinical decision-making. In order to improve the reporting quality, it is necessary to promote and actively apply the CONSORT statement for abstracts.

[Investigation of self-renewal mechanism about CD133+ cancer stem cells in human laryngeal carcinoma Hep-2 cell line].

OBJECTIVE: To investigate the self-renewal mechanism of CD133+ cancer stem cells from Hep-2 cell line. METHOD: The CD133+ cells were sorted by flow cytometry from Hep-2 cell line. Then the sorted CD133+ cells were cultured in RPMI1640. The ability of self-renewal of CD133+ cells were tested by MTT assay. mRNA and protein expression of self-renewal related genes were detected by western blot and RT- PCR. RESULT: (3.10 ± 0.21)% of Hep-2 cells expressed the membrane antigen CD133. CD133+ fraction was raised to (90.20 ± 5.51)% by flow cytometry. In vitro culture and growth curve showed CD133+ cells had more active proliferation ability than CD133- cells, which showed statistically significant difference between these two group (P < 0.01). RT- PCR and western blot results showed upregulated mRNA and protein expression of Fas, c-myc, survivin in CD133+ group (P < 0.01). In the same time, the ratio of Bcl-2/Bax gene expression was obviously increased in CD133+ group. Self-renewal related gene such as ß-catenin, SHH, SMOH and Bmi-1,Gli-1 were all up-regulated in CD133+ group both in mRNA and protein. On the contrary, PTCH gene was down-regulated. CONCLUSION: CD133 positive cells are a small proportion of a Hep-2 cell line. The results of this experiment verified that CD133 positive cells owned the properties of cancer stem cells. Upregulated anti-apoptotic gene is the foundatiom of self-renewal mechanism of CD133+ cells. Cancer stem cells related signal pathways such as Hedgehog, Wnt and Bmi-1 pathway are in state of activation. The identification of self-renewal mechanism about cancer stem cell provides a powerful tool to investigate the tumorigenic process in the larynx and to develop therapies targeting to these signal pathways.

[Investigation on biological characteristics of CD133+ cancer stem cells in human laryngeal carcinoma Hep-2 cell line].

OBJECTIVE: To investigate the biology characters of CD133+ cancer stem cells from Hep-2 cell line. METHODS: The Flow cytometry was applied to purify CD133+ cells from Hep-2 cell line. The sorted CD133+ cells were cultured in RPMI1640. The ability of migration, invasion and clonality of CD133+ cells were performed to characterize the properties of the cells. CD133+ cells and CD133- control cells were treated with paclitaxel and exposed respectively to X-rays emitted by linear accelerator with a dose of 10 Gy. The surviving rates and growth inhibition ratio of cells in two groups were detected with MTT assay to observe the resistance to irradiation and chemotherapy in CD133+ cells. RESULTS: The percentage of CD133+ cells in the unsorted and the sorted cells were 3.1% +/- 0.2% and 90.2% +/- 5.5%, respectively. CD133+ cells showed the higher proliferation and colony ability than CD133- cells. The numbers of CD133+ and CD133- cells that passed the membrane of Transwell chamber were 526 +/- 39 and 220 +/- 20 respectively (t = 22.08, P < 0.001). The colony forming units of three passages were 30.0% +/- 4.7%, 32.2% + 3.6%, 32.7% + 3.4% in CD133 cells and 15.2% +/- 2.2%, 12.0% + 2.5%, 13.8% +/- 3.3% in CD133- cells. There were statistic difference between two groups (t = 8.99, t = 14.66, t = 12.69, P < 0.01). At 24, 48, and 72 hours of treatment with paclitaxel, the cell surviving rates of CD133+ cells were 90.1% +/- 5.9%, 85.1% +/- 7.1% and 70.3% +/- 6.4% and lower than those of CD133- cells, respectively (t = 5.24, t = 8.18, t = 8.14, P < 0.01) . After radiotherapy, growth inhibition ratio of CD133+ and CD133- cells were 30.0% +/- 7.1% and 55.0% +/- 6.3% (t = 8.30, P < 0.01). CONCLUSIONS: CD133+ cells exist in a small proportion in Hep-2 cell line and they show the properties of cancer stem cells, with the resistance to irradiation and chemotherapy.