Circular RNA circCSPP1 knockdown attenuates doxorubicin resistance and suppresses tumor progression of colorectal cancer via miR-944/FZD7 axis.

BACKGROUND: Circular RNAs (circRNAs) have been reported to play vital roles in colorectal cancer (CRC). However, only a few circRNAs have been experimentally validated and functionally described. In this research, we aimed to reveal the functional mechanism of circCSPP1 in CRC. METHODS: 36 DOX sensitive and 36 resistant CRC cases participated in this study. The expression of circCSPP1, miR-944 and FZD7 were detected by quantitative real time polymerase chain reaction (qRT-PCR) and the protein levels of FZD7, MRP1, P-gp and LRP were detected by western blot. Cell proliferation, migration, invasion, and apoptosis were assessed by 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2-H-tetrazolium bromide (MTT) assay, transwell assay, or flow cytometry analysis, respectively. The interaction between miR-944 and circCSPP1 or frizzled-7 (FZD7) was predicted by Starbase 3.0 and verified by the dual luciferase reporter assay, RNA immunoprecipitation (RIP) assay and RNA pull down assay. Xenograft tumor assay was performed to examine the effect of circCSPP1 on tumor growth in vivo. RESULTS: The expression of circCSPP1 and FZD7 was upregulated while miR-944 expression was downregulated in doxorubicin (DOX)-resistant CRC tissues and cells. CircCSPP1 knockdown significantly downregulated enhanced doxorubicin sensitivity, suppressed proliferation, migration, invasion, and induced apoptosis in DOX-resistant CRC cells. Interestingly, we found that circCSPP1 directly downregulated miR-944 expression and miR-944 decreased FZD7 level through targeting to 3' untranslated region (UTR) of FZD7. Furthermore, circCSPP1 mediated DOX-resistant CRC cell progression and doxorubicin sensitivity by regulating miR-944/FZD7 axis. Besides, circCSPP1 downregulation dramatically repressed CRC tumor growth in vivo. CONCLUSION: Our data indicated that circCSPP1 knockdown inhibited DOX-resistant CRC cell growth and enhanced doxorubicin sensitivity by miR-944/FZD7 axis, providing a potential target for CRC therapy.

Simultaneous detection of four common oral Candida species from blood samples by the fluorescence polarization assay.

The genus Candida is both the commensal microbe and the opportunistic pathogen, containing approximately 200 species inhabiting in oral cavity of 53 % of the general population. Candida species can cause the diseases from local mucosal infections to systemic mycoses, even life-threatening infections in immunocompromised individuals. The timely differentiation of Candida species is important for the guidance of clinical medication. Four common Candida species in Chinese population (Candida albicans, Candida tropicalis, Candida glabrata, Candida krusei) were chosen as the targets to develop the rapid screening method in this work. Combined with amplification by asymmetric PCR, this parallel fluorescence polarization (FP) immunoassay is carried out in homogeneous solution phase. The limit of detection of the assay was shown to be 50 copies/mL in blood samples. The evaluation in multicenter manner showed excellent reproducibility and stability. The comparison between DNA sequencing and the FP immunoassay indicated that there was no significant difference between these methods. This molecular strategy-based method is simple, rapid, and feasible for identifying common Candida species and thereby holding great potential in the application of clinical laboratories.

[Effects of the traditional Chinese drug Dipsacus asperoides on the reconstruction of paradentium during the orthodontic tooth movement in rats].

PURPOSE: To observe the effects of the traditional Chinese drug Dipsacus asperoides on the construction of paradentium as well as the mechanism of action to osteoclast during the orthodontic tooth movement in rats. METHODS: Forty-eight female 8-week-old SPF Wistar rats were selected. They were randomly divided into 2 groups: Dipsacus asperoides group and control group. Then animal model for orthodontic tooth movement was established. 3 mL of NS was drenched to the control group and the Dipsacus asperoides group was given 6 g/kg per day Dipsacus asperoides decoction. The rats were executed in batch on the 7th, 14th, 21st, 28th day during the orthodontic treatment. The distances of the tooth movement were measured and slices from the periodontium of the maxillary first molar were observed under optical microscope. Measurement data were compared with t test and analysis of variance by PASW statistics18. RESULTS: The movement distance of the first molar was significantly larger in the Dipsacus asperoides group than that in the control group. The amount of osteoclast in Dipsacus asperoides group increased significantly compared with that in the control group (P<0.05). CONCLUSIONS: Dipsacus asperoides decoction is useful for the proliferation and differentiation of the osteoclast in orthodontic tooth movement. Supported by Shandong Provincial Science and Technology Development Project (Grant No.2008GG2NS02013) and Natural Science Foundation of Shandong Province (Grant No.Q2008C12).

[Effects of the first premolar extraction on the third molar angulation].

OBJECTIVE: To analyze the effects about inclinations of the second and the third molars in patients treated with or without premolar extractions. METHODS: Fifty-six adolescents were chosen and divided into the first premolar extraction and non-extraction groups, 30 and 26 patients respectively. The pre-treatment and post-treatment panoramic radiographs were made. Angles between long axis of the third molar and the occlusal plane (the second molar alike), and long axis of the second and the third molar were measured and evaluated. RESULTS: The maxillary and mandibular third molar angulations were all improved after treatment in two groups. Compared with non-extraction group, the average changes of angle between long axis of the third molar and the occlusal plane increased significantly in maxilla and mandible (P < 0.05). Average changes of angles between long axis of the second and the third molar decreased and had statistically significant difference (P < 0.05). The change of angle between long axis of mandibular second molar and the occlusal plane had statistically significant difference (P < 0.05), but there was no statistically significant difference in maxillary second molar (P > 0.05). CONCLUSION: The first premolar extraction in orthodontic treatment could improve the third molar angulations and it would promote the eruption of the third molar.