MiR-216a-5p act as a tumor suppressor, regulating the cell proliferation and metastasis by targeting PAK2 in breast cancer

OBJECTIVE

Our study aimed to investigate the expression of microRNA-216a-5p (miR-216a-5p) in breast cancer (BC) and its effect on the proliferation and metastasis of BC cells by regulating the expression of p21-activated protein kinase 2 (PAK2) gene.

PATIENTS AND METHODS

A total of 50 cases of cancer tissue specimens and corresponding para-carcinoma normal tissue specimens were collected from the breast surgery department of our hospital from July 2016 to December 2017. BC MCF-7 cell line and normal breast epithelial MCF-10A cells were cultured. MiR-NC (negative control), LV-p21-activated protein kinase 2 (PAK2) and/or miR-216a-5p mimics were synthesized and transfected. The protein and mRNA expression level in BC tissues and cells were detected by Western blot and quantitative Real Time-Polymerase Chain Reaction (qRT-PCR) assay, respectively. Additionally, the Luciferase Reporter Assays, cell proliferation detection, clone formation assays and transwell migration and invasion assay were performed to determine the functional alteration of BC cells, respectively.

RESULTS

The results of qRT-PCR demonstrated that miR-216a-5p was decreased in both BC tissues and cells compared with that in normal controls. Online target gene prediction software and Dual-Luciferase reporter assay were used for target identification, and PAK2 was identified as a functional target of miR-216a-5p in BC cells. The results were further clarified with the Western blot (WB) experiment. In vitro, cell functions were detected by Cell Counting Kit-8 (CCK-8), crystal violet staining and transwell experiment, respectively. The results indicated that decreased expression of PAK2 resulting from the up-regulation of miR-216a-5p could restrain the proliferation, clone formation, invasion and migration abilities of BC cells.

CONCLUSIONS

We showed that miR-216a-5p played a role as antioncogene in BC, which provides a new therapeutic target for the treatment of BC.

[Association between food intake and the serum total cholesterol level among adults in 9 regions of China]

Objective: To analyze the association between food intake and the serum total cholesterol(TC) level in adult Chinese population. Methods: This study included apparent healthy residents aged between 20 and 70 years who participated in the eighth round of China Health and Nutrition Study (CHNS) in 9 regions of China including Liaoning, Helongjiang, Shandong, Jiangsu, Henan, Hunan, Hubei, Guizhou provinces and Guangxi Zhuang Autonomous Region in 2009. The association between the serum TC level and the diet and other related factors were analyzed. Results: (1) Linear trend test showed that age, body mass index, waist circumference, systolic and diastolic blood pressure were positively related with serum TC level in 20-45 and 46-70 years old male and female (all P<0.01), while physical activity level was negatively related with serum TC level in 20-45 and 46-70 years old male and 46-70 years old female (all P<0.01). (2) Multivariate linear regression analysis showed that livestock meat intake was positively related with serum TC level in following populations: 20-45 years old male, β=0.133, P<0.001; 46-70 years old male, β=0.102, P=0.001; 20-45 years old male, β=0.065, P=0.041; years old female, β=0.059, P=0.045. Vegetable oil intake was negatively related with serum TC level in 20-45 years old male (β=-0.071, P=0.021). Saturated fat intake was positively related with serum TC level in 46-70 years old female (β=0.084, P=0.019). Total dietary cholesterol intake was positively related with serum TC level in male (20-45 years old, β=0.067, P=0.021; 46-70 years old, β=0.070, P=0.012), but not in female (20-45 years old, β=0.007, P=0.809; 46-70 years old, β=0.038, P=0.144). Cholesterol intake from livestock meat was positively related with serum TC level in male (20-45 years old, β=0.156, P<0.001; 46-70 years old, β=0.099, P=0.001), and positively related with serum TC level in 46-70 years old female (β=0.063, P=0.028). Cholesterol intake from egg was positively related with serum TC level in 46-70 years old male (β=0.056, P=0.032). Conclusions: Age, body mass index, waist circumference, blood pressure, blood pressure, and physical activity level are related with serum TC level. Cholesterol intake from livestock meat was the main food source that related with serum TC level, and the serum TC increases at a relatively small level after intake of total dietary cholesterol.

[Studies on the chemical composition of Lysimachia fortunei Maxim]

Two crystalline substances were isolated from the petroleum either extract of the herbal medicine Lysimachia fortunei: triacontanol and a mixture of the derivatives of the pigment 2,5-dihydroxyl-3-alkyl benzoquinone. Mass spectral examination of this pigment revealed the presence of embelin and its five homologues, of which three homologues possessing dodecane, tetradecane and hexadecane respectively in the alkyl side chain have not been reported so far.